By America you mean the US of A, right? Sorry, I'm always a bit missled by the oxymoron "civilization America".
About your question: severall of my map adaptions could easily have the "americans" added. All you have to do is replace a civilization with the Americans.
How to do so?
Download the Giant Earth map for ViSav3 linked in the first post of this thread.
Open it with the MS editor or any other simple txt editor.
Search for the following lines:
Replace them with the americans, like:
Then look for thiose lines further up:
And replace them with:
Save, load from that map directly, and voila. You might have to adjust the coordinates of the start a bit (Cherokee starting position is a bit to the west of Washington DC), maybe something around
StartingX=172, StartingY=58
Another way would be, if there are unused slots left, to add the civ there instead of replacing. In the map mentioned above this isn't possible though, as only 30 civs are acceptable.
This way should work for all maps and civs, thats why I posted this instead of doing the adaptions for you

. Plus most maps I made have no place for civs with a "rich history of 200 years"

, given that Civ4 plays over 6000 years.