High school band at the miners' Labor Day celebration, Silverton, Colorado. Labor Day is an American federal holiday observed on the first Monday in September, that celebrates the economic and social contributions of workers. By the time it became a federal holiday in 1894, thirty states officially celebrated Labor Day. Following the deaths of a number of workers at the hands of the US. military and US. Marshals during the Pullman Strike, the United States Congress unanimously voted to approve rush legislation that made Labor Day a national holiday. The form for the celebration of Labor Day was outlined in the first proposal of the holiday: A street parade to exhibit to the public "the strength and spirit de corps of the trade and labor organizations", followed by a festival for the workers and their families. Photographed by the U.S. Farm Security Administration/Office of War, September 1940.