6, Florida, Virginia, Illinois, California, Kansas, and Idaho, for certain. However, my wife and I have crossed the country twice by car. When we were still less than a year married. Once taking the I-80, I-70, I-64 route from northern CA to VA. And then once taking the southern I-10 route from FL to CA.
I know we did some serious fucking along the way, so you'd have to add at least six more states along those routes. No telling which ones.
I have fucked in a drunken state, stoned state, happy state, tired state and revenge state. Not sure how many of those are US states, but they are all New Zealand states