monochrome saidForgot to mention that I've been to NYC, Chicago, DC and Atlanta. I'm interested in knowing more about other US cities that I could visit.
Madison, Wisconsin...but you have to know what you're looking for and where to find it. Go there to interact with people instead of "seeing the sites." Go to a rowdy political meeting, get drunk at a bar, take a walk down a tree lined street with block after block of nineteenth century homes, enter into a random conversation with someone.
Madison was a hub of radical Left protest in the late 1960s. Politics, street music, anti-capitalist co-ops, block parties mixed with counterculture describe Madison at its best and most interesting.
Go to Madison and find yourself becoming someone you never knew before.
The Mifflin Street block party is held the first Saturday in May. So that won't fit into your trip plans, unfortunately.
It's the home of the state's very large central campus, the University of Wisconsin. It's also the state capital. The state capitol building is set on a square in the middle of downtown on the highest point of land on a miles long isthmus running between two lakes.
State Street runs between the campus and Capitol Square. There are interesting shops and restaurants. Unfortunately, the charm of the street has diminished over the years as large, institutional buildings - including art museums, etc. - have replaced smaller, more human scale shops, restaurants, and bars.