This photo is from the Flickr Photostream of the Library of Congress. It's from an old glass negative of the Bain News Service depicting the Independence Day Parade in New York City, July 4, 1911. There are some other interesting pictures in the collection from that day, including a sort of "parade of nations" with captions such as "Italy in New York," "Swiss in New York" and such.

With the launch of the Library of Congress pilot, Flickr began a new initiative called "The Commons." Cultural heritage institutions that join The Commons are sharing images from their photographic collections that have no known copyright restrictions as a way to increase awareness of these collections with the general public. For more information on The Commons, see http://www.flickr.com/commons. Participating organizations include the Brooklyn Museum and the Smithsonian.