A floatplane (Boeing Model 15?) takes off from the reflecting pool in front of the Lincoln Memorial. The buildings to the right are the Main Navy and Munitions Buildings, built in 1918 to provide temporary quarters for the US Military and were used throughout WWII. The buildings were torn down in 1970, and the reclaimed land is now the site of the Constitution Gardens and the Vietnam Veterans Memorial.
The Atlantic has a fascinating photo essay of historic photos of the Lincoln Memorial from its construction to the present day.
Library of Congress photo