For one, the idea of hooliganism is pretty outdated since the eighties, really.
Another thing is that North-American leagues usually well spread, sometimes throughout the whole continent, so there’s less local rivalry going on.
In all seriousness, I would say this. American sports rarely put multiple teams at the top level in the same metropolitan area. For any sport, you can count the exceptions on one hand.
If I calculated correctly, there is no drive in the EPL that takes more than about 6 hours (Newcastle United-Swansea City). For a sports fan in Minneapolis, there is only one road trip closer than that (to Green Bay for football: 5 hours). There is only one taking the same length (to Milwaukee for basketball or baseball: 6 hours). Every other trip is longer, and Minneapolis isn’t even in the worst situation. (Denver, Salt Lake City, Portland, Seattle are all worse.) Factor in the admission costs and it’s easy to see that traveling on a regular basis to support your team becomes something that only someone with a fair amount of money can do.
European-wide if you mean it exists in every country. But in most of Spain it doesn’t: it exists in a very limited amount of locations, and those people will use anything as an excuse to behave like the rabid dogs they are - if the local team loses, it if wins, if it’s not playing, if there’s elections, if there’s not, if it rains, if the sun shines, if it’s foggy…
Even though it’s the opposite of the OP, I don’t think it’s a hijack to ask why hooliganism is prevalent to the degree that it is in Europe.
Also, there’s definitely less acceptance in the US for public intoxication.
What? Eagles fans don’t count?
The games are so boring that rioting is the only excitement the fans ever get. 
My WAG is hooliganism is an outlet for xenophobic nationalism, it’s a long boat ride for American punks to beat up on Frenchmen and the like.
Having seen some of this first-hand:
it’s because Europe has had approximately 800 million stupid sectarian wars, some of them going up to very recent history. Lots of peoples’ memories are inflamed with this stuff and hooliganism is just an extension of that. Americans are much more of a united people in comparison.
While there are certainly some sectarian-inspired hooliganism (especially in Scotland), it doesn’t explain say, rival London clubs who used to fight with each other.
In support of my rival fans traveling to away games hypothesis, I submit the following:
West Ham fans travel to Columbus, Ohio and get in a brawl with Columbus Crew fans.
I think you’re right about individualism but completely wrong about brawling in bars. I bet almost every single American football game has a fight in the stadium, but they just don’t turn into widespread hooliganism. There are exceptions where there are also groups, but it is very common for a few people to get into a fight at sporting events in the USA.
It’s not uncommon to see worse violence, but I’m not sure if it would qualify overseas as hooliganism. Eagles fans throwing batteries? A Raiders-49ers games with two shootings? Dodgers fans nearly beating a Giants fan to death after a game?
I thought of this, but what about hooliganism within the UK, then? It is a problem there, no?
In general I think Americans are simply less prone to rioting than our European brethren. I remember when you’d see labor riots in France every year (not quite like the clockwork riots in South Korea, but similar)…something you just generally don’t see in the US. Oh sure, we get riled up and riot sometimes, but not nearly as frequently. Even if you look at all the ruckus supposedly from the OWS protests it’s small beer compared to any given year in many European countries.
That said, I don’t remember the Germans rioting as much at football games when I was there, nor do I recall reading much about hooliganism is the Scandinavian countries either, so isn’t this really just a few European countries where this sort of thing happens on anything like a regular basis?
USA major league football games are expensive (a decent ticket to the NE Patriots costs about $170.00).
How do the English hooligans afford the admission price (and travel to the continent)?
Most seem to be unemployed.
A few countries, and within most of those countries, a few specific groups/locations.
American football isn’t very exciting.
Well, I agree with you there. But then, soccer is about as exciting as watching paint dry IMHO. And baseball. And golf. And even motor racing doesn’t make my bunny jump. About the only sport I enjoy watching is hockey. MMV however on what does or doesn’t constitute excitement in a sport.
Our laws are a lot stricter and the jail sentences longer than those in most European countries. If two people get in a fight in the stands, chances are that both of them are going to jail for assault at least and they may never get to see another game live again because they will be banned. If a huge brawl starts because of it and someone gets really hurt or killed, they could be looking at a long prison sentence. It just isn’t worth it in a setting where you are almost guaranteed to be caught and have law enforcement and the courts follow through with the prosecution. I get the impression that European police take smaller crimes in public venues a lot less seriously than police in the U.S. There is also much less social acceptance of it.
Another factor I think is that there area number of sports to devote yourself to in the US, while there is pretty much only football in the UK. Here is the US, the NFL is king, but there are die hard fans of college football, college basketball, baseball, NASCAR, and hockey plus some others probably. So the real die-hards are split up among several sports so that a real critical mass of trouble makers is hard to come by in any one event, even if they can make the long trip to opposing teams venues.
Partly it’s a function of socio-economic class. NFL games are very expensive to attend regularly if the teams are at all popular. So, a wealthier, older crowd with more to lose by being arrested or injured.
Also, it’s not strictly true to say there’s no hooliganism in American pro sports. In major league baseball, Yankees fans have a well earned rep for brawling with fans of opposing teams. Here in LA, violence at Dodger stadium has been a huge problem, with a variety of measures taken to prevent it. In the last major incident, a fan from an opposing team was nearly beaten to death be 2 Dodger fans after the game. In football, Raiders fans, especially when the team was in Los Angeles, were also known for their inclination to fight.
This type of violence is much less organized than in European football, and in Europe, the northerners seem to be more inclined towards organized melee’s than southerners. The American individualism cited above.