George Washington warned against the development of political parties in general, actually...and as it turned out, he was the first and last president to not belong to one. As I've said before, I'd love to see what sort of ass he'd kick and gum he'd chew were he to wake up in the modern-day city that bears his name and see what's been going on.
As for why the US has almost always been a strictly two-party system...that's a very good question, actually, and probably one I may have heard answered in a past history or political science class, though I don't remember it if it was. I do know that the original two opposing political parties arose from two diametrically-opposed general viewpoints about the American system of government, most notably represented by the political philosophies of Alexander Hamilton and Thomas Jefferson; in fact, the Democratic-Republican Party of Jefferson wound up evolving into the modern-day Democratic Party, even though its original views were far more in line with what we call "conservatism" today. The main opposition parties in each era of American government were primarily opposition parties to the Democrats, so I suspect that that philosophy simply gained momentum to the point that we have today's incredibly-well-established two-party system. Interestingly enough, the Republican Party started out as something of a "third party" itself, so it isn't as though there isn't precedent for that sort of thing in American politics; except for maybe someone like Ross Perot, though, third parties seem to have had significantly more impact in the past than they have over the past several decades. I'm no political history expert, though, so don't take any of that as gospel.