Generally speaking, Labor Day, the U.S. federal holiday observed annually on the first Monday in September celebrates the American labor movement and offers workers a long weekend off from work—with plenty of time to go shopping and take advantage of big Labor Day sales.

Labor Day is the result of proposals by two 19th century union men with a similar last name, Peter J. McGuire and Matthew Maguire. What began as an excuse for union tradesmen to have a parade honoring their work became a somber day to honor working people following Chicago’s Haymarket riot in May 1886, when a labor demonstration was bombed, killing at least four people.

Labor Day in the United States should not be confused with International Workers’ Day, or May Day, observed annually on May 1. Though the days of observance stem from the same Haymarket bombing incident, they were officially made separate by President Grover Cleveland. Cleveland feared the Americanized holiday would seem too radical and supported a campaign to separate Labor Day from International Workers’ Day. What we now know as Labor Day was adopted as a federal holiday in 1894.

In the more than 100 years since then, Labor Day has shifted with the times. For example, some workers—mostly hourly retail employees—now work longer hours than on any other business day. For many others, though, Labor Day means a little less work, and a bit of extra time to travel and enjoy summer’s waning days. And, of course, many communities also still celebrate the whole reason we have Labor Day: those patriotic community parades.