Labor Day is a United States federal holiday observed on the first Monday in September, that celebrates the economic and social contributions of workers. It was first nationally recognized in 1894 to placate unionists following the Pullman Strike. With the decline in union membership, the holiday is generally viewed as a time for barbeques and the end of summer vacations
http://en.wikipedia.org/wiki/Labor_Day
http://en.wikipedia.org/wiki/Labor_Day