Labor Day is a federal holiday in the United States celebrated
on the first Monday of September to honor and recognize the
American labor movement and the works and contributions of
laborers to the development and achievements in the United
States.

Beginning in the late 19th century, as the trade union and labor movements grew, trade unionists proposed that a day be set
aside to celebrate labor. "Labor Day" was promoted by the
Central Labor Union and the Knights of Labor, which organized
the first parade in New York City. In 1887, Oregon was the first
state of the United States to make it an official public holiday.

By the time it became an official federal holiday in 1894, thirty
states in the U.S. officially celebrated Labor Day.

(From Wikipedia, the free encyclopedia)