We're two Brits who are hoping to drive a US road trip from New York to San Francisco, via New Orleans, in September next year. We only have a maximum of 3 weeks in which to do it though, and were even wondering if it could be done in 2 - is this possible?!

Obviously this will involve an awful lot of driving but we were hoping to spend a day or two in each city.

Hopefully this isn't totally unrealistic and any help would be greatly appreciated.