What year did aids first come to america or was first diagnosed here?

1981: It was first recognized in 1981, so HIV was probably here in the late 70's.

Unclear: There are cases which have been retrospectively diagnosed dating back to the 1950 era, and epidemiologic studies suggest that rare cases developed in remote areas of africa prior to that, but the major appearance was published in august 1981, although it was not known then what was causing it.