Labor Day is a U.S. federal holiday celebrated on the first Monday of September to honor the American labor movement and the contributions of workers. Its origins trace back to the late 19th century, with the first public parade held in New York City in 1882 under the auspices of the Central Labor Union and Knights of Labor—though credit for the idea is disputed between Matthew Maguire and Peter J. McGuire. Oregon became the first state to officially recognize the holiday in 1887, and in 1894, shortly after the Pullman Strike, President Grover Cleveland signed a bill making it a federal holiday, by which time 30 states already celebrated it. Interestingly, while Canada shares the same September date, more than 150 other countries honor workers on May 1 (International Workers' Day), which commemorates the 1886 Haymarket affair in Chicago. Traditionally marked by parades, picnics, and speeches from labor leaders, Labor Day also serves as the unofficial end of summer, though a 1909 effort to establish a parallel "Labor Sunday" never gained widespread popularity.