While the Civil War tore the nation in half just south of the District’s borders, it also paused building projects, like the Washington Monument (shown), and altered social and cultural patterns in D.C. Some remnants, like the forts (Reno, Totten, and Dupont, among many others), were turned into parks and still serve as reminders of the city’s transformation from defenseless town to fortified capital. D.C.’s demographics also changed during the war, when slaves walked off their owner’s plantations and joined the Union’s cause; surrounded by two slave states, the city got a population bump after the Emancipation Proclamation. The Anacostia Community Museum, which is located on the site of Fort Stanton, examines how the city evolved over time with maps and period photographs on the walls of its main gallery. Some aspects, like the rivers and Foggy Bottom’s streets, remain the same on contemporary maps, while neighborhood names like Swampoodle (present-day NoMa) and Uniontown (present-day Anacostia) remind viewers how much the District has changed in the past 150 years. The exhibition is on view daily 10 a.m. to 5 p.m., to Oct. 18, at the Anacostia Community Museum, 1901 Fort Place SE. Free. (202) 633-4820. anacostia.si.edu.