How very wrong you are. America is easily one of the best civilizations because of one word: Expansionistic. In the early game there is no better trait. With that first scout (and maybe more if you keep building them) you can zip around the map grabbing practically every Barb. Hut out there (unless your stupid enough to use America in an archipellago), and these huts usually yield a Civ. Advance each. In a matter of turns, you will have half of the Advances in that Era!!!! That's a lot. Add Industrious to that and you have a very prosperous civilization. Industriousness speeds up your workers to the point that every city is very well off when it comes to shields, food, and commerce. So what if their F-15 are utterly, utterly useless, you'll have tanks while everyone is still blowing off their own fingers with early forays into gunpowder, all thanks to that early lead you got with your scouts.