2010 EDIT - read the comments, specifically Roger Allaway's on page two or so. American soccer was as patriotic as all get out - who knew? 2010 EDIT EDIT - OH GOD DAMN IT. How the HELL was I supposed to have bothered to click on...anyway, Isle of Man has a cup competition that's older than any outside the British Isles. I don't know how we exclude it - amateur status, size of "nation," existence of "nation," FIFA membership - all those would boot out those universally recognized, including of course England, Scotland, Wales, and Northern Ireland. An "all cats must have tails" proviso has yet to be passed. I'll make the appropriate corrections in the post - it doesn't change the "continuously played" records, though. If Jersey or Guernsey or the god-damned Shetland Islands also have cup competitions from the 1700's or some crap, well, as far as I'm concerned they can sit on their thumbs and go bowling.
A few years ago, I went to this page to research where the US Open Cup stood as far as longevity. What I found:
The US Open Cup is the second oldest continuously contested soccer cup competition in the world, and you'll probably never guess the oldest.
The US Open Cup is the fourth oldest soccer cup competition outside the British Isles, and you'll probably never guess the other three.
As far as I know, I was the first one to bother to look this stuff up. Only now, years later, do I realize why. The federations involved haven't always been necessarily that proud of their records.
Let's take the oldest cup competition outside Britain. The Indian Football Federation is, to be fair, very proud of the IFA Shield - to the point of incomprehensibility:
The IFA Shield is the fourth oldest club cup competition in the world after the English and Scottish FA cup's and the Durand Cup and the Calcutta Football League is the oldest league tournament in Asia and one of the oldest leagues in the world.
Don't bother counting on your fingers to figure out how the IFA got to fourth after England and Scotland. It's not the fourth oldest, it's the sixth oldest. The others in front of India are Wales, (Northern) Ireland, and the Isle of Man. (We'll get to Northern Ireland later in the post.) The LHUSOC, in case you were wondering, clocks in at ninth.
Besides, the IFA isn't actually the FIFA representative - the AIFF is. So the real historical achievement was by a former competitor, now grumbling subordinate. That, and the huge huge success India has achieved over the years despite their massive head start, is part of the reason why you don't hear very much about the IFA Shield or the Durand Cup.
Oh...that, and the years where the tournament was restricted to white colonials. I realize American sports still count records from before black people were allowed to play, but you can also understand why an Indian federation doesn't lead off with "Colonialism - The Good Old Days!"
So, the Indian cups aren't actually administered by the Indian federation...which makes lists like this fairly problematic. Do you count India twice, or not at all? If you do, it's the oldest, or two oldest, outside the British Isles. If not, well, then it's Spain, assuming those are all the same trophy and tournament. Who the hell knows.
Why doesn't the CSA crow about their distinction? Well, they might not even know about it. According to the CSA website, it goes all the way back to 1987, and misspells "trophy" to boot. But Dave Litterer says it's a lot older, and y'know, I'll go with him. Assuming it's the same competition, which I can't guarantee.
So we're at nine, after England, Scotland, Wales, Northern Ireland, Isle of Man, India, Spain, and Canada. Both India and Canada's tournaments, being loyal members of the Commonwealth of Nations, took a hiatus during Britain's time of greatest trial. India also took a break to have a massively destructive partition. Spain played through the World Wars, but had an inconvenient civil war. That's what rockets the US Open Cup all the way to second in the continuously played category.
The oldest continuously played tournament is Northern Ireland. And the Irish Football Association seems to be even more ashamed of their cup competition than either Canada or the United States. Historical results? Dream on.
Why so shy about their history? Well, in order to have the oldest and second-oldest continuously played tournament in the world, you kind of had to ignore the big wide world. It was embarrassing enough for Eamonn de Valera to say "We of the Irish Free State will do nothing to stop Adolf Hitler, and history will undoubtedly look very kindly on my decision!" That a part of the United Kingdom itself protested against, and was ultimately exempted from, conscription...well, you can imagine that would cure any temptation to brag about lingering at home having kickabouts.
A glance at the winners of the Irish Cup during the wars tells the story quite loudly. If the CSA and the USSF don't list their winners due to incompetence, there might be other reasons why the IFA doesn't trumpet these lists.
Seeing "Belfast Celtic" so prominently displayed during wartime results has to rankle, since Belfast Celtic was basically Glasgow Celtic, and the entire rest of the IFA was Glasgow Rangers. You can celebrate their checkered past here, because the IFA certainly won't. (What is it with divisive federations called "IFA", anyway?)
I think this is why in the past the USSF hasn't celebrated the Open Cup's longevity. Yes, baseball and football played through the wars, but those sports took more than a little heat for it. It was also assumed that their games' healthy stars would do their part, or the draft board would do it for them. (The St. Louis Browns won their only pennant in 1944, because every healthy American man between 18 and 45 was otherwise occupied.)
But soccer had a distinct odor of foreignness and un-Americanness (distinct but similar strains of disapproval in the 40's). One might be tempted to conclude that from 1941 to 1945 German and Italian teams dominated isn't borne out by team names - there did seem to be a number of Italian names on Pittsburgh Gallatin in 1942, but that doesn't necessarily mean they were non-citizens (let alone Duce sympathizers). Brooklyn Hispano won more on the strength of Billy Gonsalves than from theoretical Spanish refugees, and I can come to no racist conclusions about Brookhattan based on Josh's incredible site. (Non-citizen Joe Gaetjens apparently didn't join Brookhattan until later that decade.)
But if everyone from Glenn Miller to Jimmy Stewart had to join up, there was certainly no percentage in marketing players' love of sport over country...whichever country that happened to be. Mainstream sports had to put on a very great show of patriotism during those years, and they still had to surrender DiMaggio and Ted Williams to the cause. It was not a coincidence that the national anthem began to be played before every game during World War II.
So the US Open Cup does have the third longest streak in the world, but seen in the light of politics, it seems to be a record that has at the very least a backhanded connotation. Which is why you have to dig through RSSSF to find this sort of thing, rather than read it splashed on various websites.