A Navy Destroyer in Union Square 1917

I visit Shorpy: The 100 Year-Old Photography Blog almost everyday, they post a wonderfully random selection of old photography (click on the image to enlarge) I find the above image amazing, it's explained on the blog this way:

New York, 1917. "Landship Recruit on Union Square." The U.S.S. Recruit, a wooden battleship erected by the Navy, served as a World War I recruiting station at Union Square from 1917 to 1920, when it "set sail" for Coney Island. This is the first in a series of photographs depicting life around and aboard the landlocked boat. 5x7 glass negative, George Grantham Bain Collection.