"Labor Day in the United States is a public holiday celebrated on the first Monday in September. It honors the American labor movement and contributions workers have made to the strength, prosperity, and well-being of their country."
"Labor Day was promoted by the Central Labor Union and the Knights of Labor, who organized the first parade in New York City. After the Haymarket Massacre in Chicago on May 4, 1886, U.S. President Grover Cleveland feared that commemorating Labor Day on May 1 could become an opportunity to commemorate the affair. Therefore, in 1887, the United States holiday was established in September to support the Labor Day that the Knights favored."