Old Town Alexandria is compact and walkable, with most of the main sights within a few blocks of each other. The colonial and Revolutionary-era history is the main draw, though the African American heritage sites are equally important and often overlooked.
The key historic sites are Christ Church — where Washington worshipped — Gadsby's Tavern, and the Friendship Firehouse. The Alexandria Black History Museum is essential context for the fuller story of the city. For the best single afternoon, walk King Street from the waterfront to the historic district, stopping at whatever catches you.