Check out this great old photo of 7th and Pennsylvania Ave. during World War I.

Washington, D.C., circa 1918. "World War I. Food Administration electric signs, 7th Street and Pennsylvania Avenue N.W." National Photo Co.
Washington, D.C., circa 1918. “World War I. Food Administration electric signs, 7th Street and Pennsylvania Avenue N.W.” National Photo Co.

Source: Flickr