Hey i live in the area and you have nothing to worry about in alexandria. you do not need an id to get into the senate buildings and congress. but you need an id for the white house because they do random searches. the smithsonian is no problem as well as the national mall. there is no ice in the area but you see more federal agents from other departments that can detained you as good as ice. to summarize, have fun d.c. wont be a problem.