“Mr. Lincoln’s Washington: A Civil War Portfolio” documents the nation’s capital during the Civil War, focusing on the city itself more than its role as the Union’s seat of power. The National Portrait Gallery’s small exhibit offers a colorful look at a nearly primitive city 150 years ago; at the war’s outset, cows grazed on the Mall; the Washington Monument was an unfinished spike; the U.S. Capitol had no dome; and all three landmarks were in close proximity to a fetid open canal. The war cast a pall, of course, but the exhibit also notes some lighter moments. In 1864, as President Lincoln was visiting the troops at Fort Stevens, a battle erupted, and a young officer shouted to the 6-foot-4 president, “Get down, you fool!” The core of the exhibit is photographic, the exhibit’s biggest disappointment is its almost exclusive use of modern reproductions of the vintage photographs; one would have thought the National Portrait Gallery could have rustled up some originals. The exhibition is on view 11:30 a.m. to 7 p.m. daily to Jan. 25, 2015, at the National Portrait Gallery, 8th and F streets NW. Free. (202) 633-8300. npg.si.edu.