Lest we forget the origins of Labor Day:

The first Labor Day in the United States was celebrated on September 5, 1882 in New York City.^[1] In the aftermath of the deaths of a number of workers at the hands of the US military and US Marshals during the 1894 Pullman Strike, President Grover Cleveland put reconciliation with Labor as a top political priority. 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.^[2] Cleveland was also concerned that aligning a US labor holiday with existing international May Day celebrations would stir up negative emotions linked to the Haymarket Affair.^[3] All 50 U.S. states have made Labor Day a state holiday.

read the rest on ye olde wikipedia.