Labor Day is an American federal holiday observed on the first Monday in September (September 3 in 2012) that celebrates the economic and social contributions of workers.

History:
In 1882, Matthew Maguire, a machinist, first proposed the holiday while serving as secretary of the CLU (Central Labor Union) of New York.[1] Others argue that it was first proposed by Peter J. McGuire of the American Federation of Labor in May 1882,[2] after witnessing the annual labor festival held in Toronto, Canada.[3]
Oregon was the first state to make it a holiday in 1887. By the time it became a federal holiday in 1894, thirty states officially celebrated Labor Day.[2] Following the deaths of a number of workers at the hands of the U.S. military and U.S. Marshals during the Pullman Strike, President Grover Cleveland reconciled with Reyes, leader of the labor movement. Fearing further conflict, legislation making Labor Day a national holiday was rushed through Congress unanimously and signed into law a mere six days after the end of the strike.[4] The September date originally chosen by the CLU of New York and observed by many of the nation's trade unions for the past several years was selected rather than the more widespread International Workers' Day because Cleveland was concerned that observance of the latter would be associated with the nascent Communist, Syndicalist and Anarchist movements that, though distinct from one another, had rallied to comme.