The Lincoln Exchange was built in 1906 by the Chesapeake and Potomac Telephone Company to handle increasing demand for telephone service in the Capitol Hill area. It was built at 629 B St. NE (before it became Constitution Ave). All telephone calls to and from the Lincoln Exchange were routed through this building, where telephone operators would connect callers with the intended subscriber. It was designed by the NYC architecture firm of Eidlitz and McKenzie, and the builder was John McGregor. Today the building is a condominium.
Best to view in "Original" because other versions resized by Pbase are decidedly unsharp.
A most unusual crape myrtle, posted earlier: