Feel free to add/delete Excuse the odd mistake, strange characters etc. You may find some teams missing because they were at one time known as something else, in which case they may be bracketed. AFC Lancaster Lions Albany Capitals (1988–89) Albany Capitals (1990–91) (New York) Allentown/Bethlehem Hungarian Almas Americus A. A. (1895) Ansonia FC Arizona Condors (1989) Arizona Condors (1990) (Arizona) Atlanta Apollos Atlanta Chiefs Atlanta Chiefs (1979) Atlanta Ruckus (1995–96) (Georgia) Atlanta Silverbacks (1995–2004) (as Atlanta Ruckus 1995–1998) Atlanta United FC Babcock & Wilcox (1915–1919, 1920–1921) Baltimore Americans (1934/35-48/49, as Baltimore Canton in 1934/35-35/36; as Baltimore S.C. in 1936/37-41/42) Baltimore Americans (1938/39-41/42, as Baltimore German in 1938/39) Baltimore Bays (1972–73, as Baltimore Stars in 1972) Baltimore Comets Baltimore Flyers (1966/67-67/68; as Baltimore St. Gerards in 1966/67) Baltimore Pompei (1953/54-60/61, as Baltimore Rockets in 1953/54-56/57) Baltimore S.C. (1943/44-47/48) Bayonne Bayside (1898–1899) Bethlehem Steel F.C. Bethlehem Steel F.C. (1917–1921) Bethlehem Steel F.C. (1921/22–27/28, 1930, as Philadelphia Field Club in 1921/22) Bethlehem Steel F.C. 1928-1929, fall 1929 Boca Juniors (1961/62-63/64, as Inter-Brooklyn Italians in 1961/62; as Inter S.C. in 1962/63) Boston Beacons Boston Bears (soccer) (1931–32) Boston Bolts (1988–89) Boston Bolts (1990) (Massachusetts) Boston Bulldogs (1997–2000) (as Worcester Wildfire 1997–1998) Boston Minutemen Boston Tigers (1963/64, 1965/66-67/68, as Boston Metros in 1963/64) Boston Wonder Workers (1924/25–30) Bradford Marshlanders (1977 - 1982 - ?) Brampton Kicks (? - 1993, ?1994) Brantford City (1931 - 1934) Brantford Cockshutts (1928 - 1930; 1948) Bridgeport Hungaria (1930, as Newark for last 5 games) Bronx United (1910–1915) Brooklyn F.C. (1933/34, withdrew after 12 games) Brooklyn Field Club (1909–1916) Brooklyn Hakoah (1929, merged with New York Hakoah to form Hakoah All-Stars Brooklyn Hakoah (1948/49-55/56, replaced Brooklyn Wanderers in 1948/49 season; merged with New York Americans to become New York Hakoah after 1955/56 season) Brooklyn Hispano (1933/34-55/56, as Brooklyn Giants in 1942/43) Brooklyn Italians (1956/57-60/61, merged with Inter S.C. to become Inter-Brooklyn Italians after 1960/61 season) Brooklyn Morse Dry Dock (1919–1920) Brooklyn Robins Dry Dock (1918–1921) Brooklyn St. Mary's Celtic (1933/34-41/42, as Brooklyn Celtic in 1933/34-34/35; replaced Brooklyn F.C. during 1933/34 season) Brooklyn Wanderers (1895–1899) Brooklyn Wanderers (1922/23–31) Brooklyn Wanderers (1932–33) Brooklyn Wanderers (1942/43-48/49, withdrew after 1 game in 1948/49) Buffalo Blazers (1976 - 1978) Bunker Hill F.C. (1920) Calgary Boomers Calgary Kickers/Calgary Strikers (1987–1989) Calgary Mustangs (2002–2004) (as Calgary Storm 2002–2003) California Emperors (1990) (California) California Jaguars (1995–1998) California Kickers (1987–89); Hollywood Kickers (1986) California Sunshine (1977–80) – based in Orange, California and Oxnard, California. California Surf Canadian National Railway (1929 - 1932) Caribous of Colorado Carolina Dynamo (1997) Carolina Lightnin' (1981–83) Carolina RailHawks Centreville A.C. (1895–1899) Charleston Battery (1997–2004) Charlotte Eagles (2001–2003) Chicago Americans (1972, only played a few games) Chicago Cats (1975–76) Chicago Fire Chicago Mustangs Chicago Spurs Chicago Sting Chivas USA Cincinnati Comets (1972–75) Cincinnati Riverhawks (1998–2003) Clark A.A. (East Newark Clark A.A.) (1906–1907, 1908–1909) Cleveland Cobras (1974–1981) Cleveland Stokers Colombo (1959/60) Colorado Foxes (1990–96) (Colorado) Colorado Rapids Columbus Crew SC Columbus Magic (1979–80) Connecticut Bicentennials Connecticut United FC Connecticut Wolves (1995–2001) Connecticut Yankees (1972–78, as Nor'East United in 1972, as Connecticut Wildcats in 1973–74) Corinthians (1928, 1929) Cosmos D.C. United Dallas Americans (1983) Dallas Tornado Delaware Copperheads Delaware Wings (1972–74) Denver Dynamos Detroit Besa (1981) Detroit Cougars Detroit Express Detroit Express (1981–83) Detroit Mustangs (1972–73, as Detroit S.C. earlier in 1972) Disston A.A. (Tacony Disston or Philadelphia Disston) (1917–1918, 1919–1921) Domestics Dublin F.C. (1916–1917) Dynamo Latino (? - 1985) East End Football Club Eastern Conference Edmonton Aviators (2004) Edmonton Brickmen (1986) Edmonton Brickmen (1987–1990) Edmonton Drillers El Paso Patriots (1997–2003) Essex County F.C. (1906–1907) F.C. Portland (1985–88); Portland Timbers (1989) F.C. Seattle (1985–87); Seattle Storm (1988–89) Fall River F.C. I (1924/25–1931, as Providence Clamdiggers in 1924/25–27/28; as Providence Gold Bugs in 1928/29–30; as Fall River Football Club in 1931; absorbed New Bedford Whalersduring spring 1931 season; absorbed by New York Yankees before fall 1931 season) Fall River F.C. II (1932) Fall River Marksmen (1921–1930) originally as Fall River United in 1921/22; merged with New York Soccer Club to form New York Yankees Fall River Rovers Fall River S.C. (1957/58-62/63) FC Dallas FC Edmonton Fergus (1948) Fleisher Yarn (1924/25) Fort Lauderdale Strikers Fort Lauderdale Strikers (1988–89) Fort Lauderdale Strikers (1990–94) (Florida) Galicia-Honduras (1933/34-61/62, as New York Brookhattan in 1933/34-37/38; as Brookhattan in 1938/39-56/57; as Brookhattan-Galicia in 1957/58-58/59; as Galicia S.C. in 1958/59-60/61, merged with non-league Honduras after 1960/61 season) General Motors (1928) Georgia Generals (1982, as Cleveland Stars in 1972–73; as Cleveland Cobras in 1974–81) Golden Bay Earthquakes Golden Gate Gales (1980) – based in San Francisco. Gorden Rangers (1906) Guelph Taylor-Forbes (1928) Hakoah All-Stars (1929/30–1932), merger of New York Hakoah and Brooklyn Hakoah Haledon Thistles (1915–1916) Hamilton Apollos (?1968, ?1969, 1970 - 1972) Hamilton Austins (1951) Hamilton British Imperials (1948) Hamilton City (1927 - 1940; 1950; 1973 - 1975) Hamilton Cougars (1959) Hamilton Croatia (?1968, ?1969, 1970 - 1976) Hamilton Homer (?1968, ?1969, 1970; 1973 - 1975) Hamilton Hungaria (1958) Hamilton Italo-Canadians (1958 - 1960; 1972 - 1979) Hamilton Primos (1967, ?1968, ?1969) Hamilton Steelers (1981, 1982) Hamilton Steelers (1987–1991) Hamilton Stelcos (1939, 1940; 1947) Hamilton Thistles (1927 - 1938) Hamilton Westinghouse (1948 - 1955) Hamilton White Eagles (1993, 1995) Harrison Alley Boys (1915–1916) Harrison Field Club (1921/22–22/23, as Harrison Soccer Club in 1921/22) Hartford Americans (1927/28) Hartford Bicentennials Hartford S.C (1964/65-68, as Hartford Kings in 1966/67 & 1968) Hershey Wildcats (1997–2001) Hollywood Inn F.C. (1907–1908) Holyoke Falcos (1921/22) Houston Dynamo Houston Hurricane Houston Stars Icon FC IFK Maryland Indiana Blast (1999–2003) Indiana Tigers (1973–74, as Gary Tigers in 1973) Indianapolis Daredevils (1974–79, as Rhode Island Oceaneers in 1974–76; as New England Oceaneers in 1977) Indy Eleven Inter S.C. (1960/61, merged with Brooklyn Italiansto become Inter-Brooklyn Italians after 1960/61 season) International A.C. (1895–1896) IRT Rangers 1928-1929, fall 1929 Jacksonville Armada FC Jacksonville Cyclones (1997–1999) Jacksonville Tea Men Jacksonville Tea Men (1983) Jersey A.C. (1907–1908, 1909–1918) Jersey City Celtics (1921/22, folded after 5 games) Jersey City (1928/29) Kansas City Spurs Kearny A.C. (1906–1907) Kearny AC (1897–1898) Kearny Arlington (1897–1899) Kearny Cedars (1898–1899) Kearny Celtic (1933/34-50/51, as Kearny Irish in 1933/34-41/42) Kearny Erie (Harrison Erie S.C. or Erie A.A.) (1919–1921) Kearny Federal Ship (1919–1921) Kearny Rangers Kearny Scots (1895–1899) Kearny Scots (1933/34-52/53, technically as Kearny Americans in 1941/42-52/53) Kearny Scots (Scots-Americans or Scottish-Americans) (1906–1918) Kearny Stars (1906–1907) Kenwoods (1941) Kitchener Concordia (?1968, ?1969, 1970, ?1971) Kitchener Kickers (1965, 1966, ?1967, ?1968, ?1969) Kitchener Maple Leafs (?1971, 1972) Kitchener Spirit/Kitchener Kickers (1990–1991) Kosova Albanians (1997) LA Galaxy Las Vegas Quicksilvers Las Vegas Seagulls (1979) Le Tricolore de Montréal (1955?) Lehigh Valley Steam (1999) Liptons (1941) London City (1973 - 1997) London CNR (1928) London German Canadians (?1968, ?1969, 1970 - 1972) London Lasers (1990 & 1992) London Marconi (1984 - 1989) Long Island Express Long Island Rough Riders (1997–2001) Los Angeles Aztecs Los Angeles Heat (1986–89) Los Angeles Heat (1990) (California) Los Angeles Salsa (1993–94) (California) Los Angeles Skyhawks (1976–79) Los Angeles Toros Los Angeles Wolves Ludlow Lusitano (1955/56-57/58, as Ludlow S.C. in 1956/57) Maryland Bays (1988–89) Maryland Bays (1990–91) (Maryland) Maryland Mania (1999) Mass United FC McKinnons (1929) Memphis Rogues Miami Americans (1976–80, as New Jersey Americans in 1976–79) Miami FC Miami Freedom (1990–92) (Florida) Miami Fusion Miami Gatos Miami Sharks (1988–89) Miami Toros Milwaukee Rampage (1997–2002) Milwaukee Wave United (2003–2004) Minnesota ? FC Minnesota Kicks Minnesota Strikers Minnesota Thunder (1997–2004) Minnesota United FC MLS Project 40 (1998–2000) Montreal Alouettes (1959) Montreal Cantalia (1958 - 1960; 1964) Montreal Carsteel (1927 - 1948 - ?) Montreal Castors (1975 - 1978) Montreal CNR (1928 - ?) Montreal Concordia (1960, 1961) Montreal Hungaria (1959, 1960) Montreal Impact Montreal Impact (1993–96) (Quebec) Montreal Impact (1995–2004) Montreal Manic Montreal Maroons (1927) Montreal Olympique Montreal Sparta (1958) Montreal Stars (1979) Montreal Supra (1988–1992) Montreal Ukrainians (1959, 1960; 1964) Nashville Diamonds (1982) Nashville Metros (1997–2001) (as Tennessee Rhythm 1999–2000) New Bedford Whalers II New Bedford Whalers III, merger of New York Yankees and Fall River F.C. I New Bedford Whalers Spring 1929 New Brunswick Hungarian (1963/64-67/68, as New Brunswick Hungarian Americans in 1963/64-66/67) New England FC New England Revolution New England Sharks (1981) New England Tea Men New Hampshire Bobcats FC New Jersey Brewers (1972–75, as New Jersey Shaefer Brewers in 1972) New Jersey Eagles (1990) (New Jersey) New Mexico Chiles (1990) New Mexico Chiles (1990) (New Mexico) New Orleans Storm (1997–1999) (as New Orleans Riverboat Gamblers 1997) New York Americans (1931–33) New York Americans (1933/34-55/56, merged with Brooklyn Hakoah to become New York Hakoahafter 1955/56 season) New York Brookhattan (1933) New York Celtics 1928 New York Centaurs (1995) New York Centaurs (1995) (New York) New York City FC New York Clan MacDonald (1907–1908, 1913–1915) New York Cosmos (1970-1985) New York Cosmos New York Eagles (1978–79, 1981) New York F.C. (1916–1921) New York Fever (1996) New York Fever (1996) (New York) New York Field Club (1921/22–23/24) New York Field Club (1932) New York Football Club New York Generals New York Giants II, originally played as Paterson F.C., later changed name to New York Soccer Club New York Giants III, previously played as Indiana Flooring and as New York Nationals New York Giants 1928-1929, fall 1929 New York Hakoah 1928-1929, fall 1929 New York Hakoah-Americans (1956/57-63/64, as New York Hakoah in 1956/57-61/62) New York Hispano 1928-1929, fall 1929 New York Hungaria Spring 1929; as Victoria Hungaria in fall 1929 New York Inter (1965/66-69, as Inter S.C. in 1965/66) New York IRT (1919) New York Red Bulls New York Thistle (1895–1896) New York Thistles New York United (1971–81, as New York Greeks in 1971–72; as New York Apollo in 1973–79) New York Yankees, merger of Fall River Marksmen and New York Soccer Club Newark Americans (1930–32) Newark Caledonians (1912–1914) Newark Caledonians (1895–1896) Newark F.C. (1906–1911, 1912–1915) Newark Falcons (1954/55-66/67, as Elizabeth Falcons in 1954/55-58/59; as Falcons S.C. in 1959/60-61/62; as Falcons-Warsaw in 1962/63-63/64) Newark Hearts (1906–1908) Newark Ironsides (1916–1917) Newark Portuguese (1951/52-62/63, 1964/65-67/68) Newark Portuguese Fall 1929 Newark Sitch (1962/63-63/64, 1965/66-70, as Newark Ukrainian Sitch in 1962/63-68) Newark Skeeters (1923/24–28/29, withdrew during season) Newark Skeeters 1928-1929, fall 1929 North York Rockets (1987–1992) North York Rockets (1993) North York Talons (1996, 1997) Nova Scotia Clippers (1991) Oakland Buccaneers (later known at Golden Bay Buccaneers (1976–77) Oakland Clippers Oakland Stompers Oakville CW (1996) Oklahoma City Slickers (1982–83) Olimpia (1965/66-66/67) ONT's Orange County Waves (2000) (as Orange County Zodiac (1997–1999)) Orlando City SC Orlando Lions (1990) (Florida) Orlando Sundogs (1997) Oshawa Italia (1962) Ottawa Fury FC Ottawa Intrepid/Ottawa Pioneers (1987–1989) Ottawa Sons of Italy (?1968, ?1969, 1970, ?1971) Ottawa Tigers (?1971, 1972 - 1978) Paterson Crescent (1897–1898) Paterson F.C. (1917–1920) Paterson F.C. (1936/37-40/41, as Newark Germans in 1933/34-36/37; moved to Paterson during 1936/37 season; as Paterson Caledonian1936/37-37/38, absorbed amateur Trenton Highlanders after 1937/38 season and moved to Trenton; as Trenton Highanders in 1938/39) Paterson Football Club Paterson Rangers (1906–1915) Paterson True Blues (1897–1988) Paterson True Blues (1906–1915) Paterson Wilberforce (1909–1914) Pawtucket Rangers (1921/22–32/33, as J&P Coats in 1921/22–28/29) Penn-Jersey Spirit (1990–91) (Pennsylvania) Pennsylvania Stoners (1979–83) Philadelphia Atoms Philadelphia Celtic (1922/23–27/28, as Philadelphia Field Club in 1922/23–26/27) Philadelphia Centennials 1928-1929 Philadelphia Field Club (1928/29) Philadelphia Field Club (1929, as Bridgeport Bears earlier in 1929) Philadelphia Fury (1978-80) Philadelphia Fury Philadelphia Merchant Ship (1918–1920) Philadelphia Nationals (1936/37-53/54, as Passon Phillies in 1936/37-37/38; as Philadelphia in 1938/39; as Philadelphia Passon in 1939/40-40/41) Philadelphia Spartans (1969–72) Philadelphia Ukrainians (1957/58-63/64, 1965/66-70, as Ukrainian Nationals in 1957/58-63/64 & 1965/66-67/68; replaced Philadelphia Ukrainiansduring 1957/58 season) Philadelphia Union Pittsburgh Cannons (1972) Pittsburgh Miners (1975) Pittsburgh Phantoms Pittsburgh Riverhounds (1999–2003) Ponta Delgada S.C. (1951–53) Portland Timbers Portland Timbers (1975-82) Portland Timbers (1990) Portland Timbers (2001–2004) Puerto Rico FC Puerto Rico Islanders Puerto Rico Islanders (2004) Quebec Selects (1974) Queen City (1962) Queens Bohemians (1932–33) Raleigh Capital Express (1997–2000) (as Raleigh Flyers 1997–1998; Raleigh Express 1999) Rayo OKC Real Salt Lake Real Santa Barbara (1989–1990) Richmond Hill Kick (? - 1993, ?1994) Richmond Kickers (1997–2004) Riversides Rochester Flash (1981–82) Rochester Lancers Rochester Lancers (1967/68-69, 1970-1980) Rochester Raging Rhinos (1996) Rochester Raging Rhinos (1997–2004) Roma S.C. (1964/65-67/68) Sacramento Geckos (1998–1999) (as Albuquerque Geckos (1998)) Sacramento Gold (1976–80, as Sacramento Spiritsin 1976–77) Sacramento Senators (1989) Salt Lake Sting (1990–91) (Utah) San Antonio Scorpions San Antonio Thunder San Diego Flash (1995–2001) (as Colorado Foxes (1995–1997)) San Diego Jaws San Diego Nomads (1986–89) San Diego Nomads (1990) (California) San Diego Sockers San Diego Toros San Francisco Bay Blackhawks (1989) San Francisco Bay Blackhawks (1990–92) San Francisco Bay Seals (1998–2000) (as Bay Area Seals (2000)) San Francisco Deltas San Jose Earthquakes San Jose Earthquakes San Jose Earthquakes (1985–88) Santa Barbara Condors (1977) Scarborough Astros (1994?, 1995, 1996) Seattle Sounders Seattle Sounders FC Seattle Sounders (1994–96) Seattle Sounders (1995–2004) Seattle Storm (1990) (Washington) Serbian White Eagles (1970 - 1980) Shawsheen Indians (1925/26) Soccer Portugais du Quebec (1970) Southern California Lazers (1978) – based in Torrance, California. Sporting Kansas City Springfield Babes (1926/27) St. Andrews/Earlscourt (1955) St. Catharines (Roma) Wolves (1978 - 1997) - (St. Catharines Roma 1978 - 1994; St. Catharines Wolves 1995; St. Catharines Roma Wolves 1996, 1997) St. Catherines Heidelberg (1971 - 1978) St. George F.C. (1913–1914) St. Louis Mules (1972, as St. Louis Frogs later in 1972) St. Louis Stars (became California Surf) Staten Island Vipers (1998–1999) Sudbury Cyclones (1976 - 1980) Sudbury Italia (1965 - 1967) Sudbury (1971) Syracuse Salty Dogs (2003–2004) Syracuse Suns (1969–71, 1973–74, as Syracuse Scorpions in 1969–70; folded after 5 games during 1974 season) Tacoma Tides (1976) Tampa Bay Mutiny Tampa Bay Rowdies (1975-84) Tampa Bay Rowdies Tampa Bay Rowdies (1990–93) Team America Team Hawaii Thistles Tiffany Rovers Todd Shipyards (1921/22) Toronto Abruzzi (1964, 1965) Toronto Azurri (1965) Toronto Blizzard Toronto Blizzard (1971-84) Toronto Blizzard (1986-1993) Toronto British Consols (1934 - 1939) Toronto Canadian Scots (1957, 1958) Toronto Canadians (1979) Toronto City (1948) Toronto CNR (1928) Toronto Congasco (1933) Toronto Croatia (1963 - 1982 - ? - 1993; 1997) Toronto Dimano (1982 - ?) Toronto East End Canadians (? = 1949 - 1956) Toronto England United (1935 - 1941) Toronto Estonia (1962, 1963) Toronto Falcons Toronto Falcons (1976 - 1982) Toronto FC Toronto First Portuguese (1965 - 1981) Toronto Greenbacks (1947) Toronto Hakoah (1954; 1964, 1965) Toronto Hellas (1965 - 1967, ?1968, ?1969, 1970) Toronto Hungaria (1952 - 1975) Toronto Inter-Roma (1967, ?1968, ?1969) Toronto Italia (1953 - 1960) Toronto Italian Virtus (1962, 1963) Toronto Jets (1995) Toronto Lynx (1997–2004) Toronto Macedonia (1974 - 1977) Toronto Macedonians (1962) Toronto Malta United (1957, 1958) Toronto Maple Leafs (1928 - 1941) Toronto Maroons (1934) Toronto Melita (1973 - 1975) Toronto Metros Toronto Metros-Croatia Toronto Mississauga Hungaria (1977, 1978) Toronto Oakwoods (1950) Toronto Olympia (1952 - 1965) Toronto Panhellenic (1976 - 1982 - ?) Toronto Polish White Eagles (1952 - 1961) Toronto Polonia (1964; 1973) Toronto Rockets (1994) (Ontario) Toronto Scottish (1927 - 1941; 1950 - 1952) Toronto Serbians (1979) Toronto Sparta (1956 - 1960) Toronto St. Andrews (1950) Toronto Supra (1996, 1997) Toronto Transit Commission (1928 - 1934) Toronto Tridents (1954 - 1960) Toronto Ukrainia (1977 - 1981) Toronto Ukrainians (1950 - 1967, ?1968, ?1969) Toronto Ulster United (1927 - 1941; 1947 - 1961) Toronto White Eagles (1967, ?1968, ?1969) Trenton Americans (1953/54-54/55) Trenton Athletics (1948/49-50/51) Tulsa Roughnecks Uhrik Truckers (1933/34-64/65, as Philadelphia German-Americans in 1933/34-40/41; as Philadelphia Americans in 1941/42-53/54; became Uhrik Truckers during 1953/54 season) Utah Golden Spikers (1976, as Utah Pioneersearlier in 1976 season) Vancouver 86ers (1987–1992) Vancouver 86ers (1993–96) (British Columbia) Vancouver Royals Vancouver Whitecaps Vancouver Whitecaps FC Vancouver Whitecaps (1995–2004) (as Vancouver 86ers (1995–2000)) Victoria Riptides (1985) Victoria Vistas (1989–1990) Virginia Beach Mariners (1997–2004) (as Hampton Roads Mariners(1997–2000; 2002)) Washington Cavaliers (1971–72, as Virginia Capitol Cavaliers in 1971) Washington Darts Washington Darts (1967/68-69, as Washington Britannia in 1967/68) Washington Diplomats Washington Diplomats (1981) Washington Diplomats (1990) (Washington, D.C.) Washington Stars (1990) (Washington, D.C.) Washington Whips Welland (1948) West Hudson A.A. (1906–1907, 1908–1918) West New York Burns Club (1906–1907) Willy Overland (1928) Windsor Rovers (1927) Windsor Stars (1975 - 1978) Windsor Teutonia (?1965, 1966, 1967 - ?1968, ?1969) Windsor Wheels (? - 1993, ?1994) Winnipeg Fury (1987–1992) Winnipeg Fury (1993) Woodbridge (? - 1993, ?1994) Worcester Astros (1967/68-75, as Fall River Astrosfrom 1967/68-68; as Boston Astros in 1968–75; moved to Worcester at end of 1975 season)
Great list. alot of work went into that! just FYI about my local team, The Charleston Battery started in 1993 not 1997 and are still playing
David Litterer's American soccer history archives site hasn't been updated much in the last few years, but there's a master list of teams since 1894 on that site that would be helpful. It's broken into three parts alphabetically. Here's the first: http://homepages.sover.net/~spectrum/soccerclub.html
Yep, I did that with Riverhounds and Kickers too and I seem to have missed several USL teams. Charlotte Independence FC Cincinnati Harrisburg City Islanders Louisville City FC Ottawa Fury FC Colorado Springs Switchbacks FC Oklahoma City Energy FC Phoenix Rising FC Real Monarchs SLC Reno 1868 FC Rio Grande Valley FC Toros Sacramento Republic FC Saint Louis FC San Antonio FC Swope Park Rangers KC I've excluded B teams (I think). That takes me up to 553, that's probably more than the UK, so you can't say the US and Canada haven't tried.
In order to get to the 553rd best club in England, you have to go down to the ninth level, which has 14 leagues.
Pretty much every team below 5 is listed as semi-pro. They were amateurs until the 1960s. THe teams I posted above are listed as pro.
for Cleveland, you forgot: Cleveland Caps Cleveland City Stars the Cobras were known as the Cleveland Stars at one point. Is this just outdoor or does it include indoor?
Some of the ASL/APSL from 25+ years ago are the same teams. Maryland Bays, Boston Bolt, Fort Lauderdale Strikes, et al, for example, do not need to be split. Kudos for realizing that the Washington Diplomats of 1981 (relocated Detroit team) was a different team than the 1980 one. The third team with that name started in 1988, as did most of the other ASL sides. Unlike the Strikers and Diplomats, the Tampa Bay Rowdies from the old NASL was the same as in the 1988 ASL. No idea if the current Cosmos is the same as the old NASL one. Not to me, but it all depends on your definition. Some USL teams are missing. Real Maryland Monarchs and Western Mass jump out at me initially. From the current ASL, you missed the Evergreen Diplomats and the Western Mass entity, but I see others listed (Fury, IFK, Long Island Express). You count the Delaware Copperheads, but they became the Delaware Stars for the ASL season. no idea if the exbibition matches in 2015 were paid or not. You can include the United Soccer League (1984-1985) teams as well.