Why most Americans no longer honor unions on Labor Day

Labor Day was once the nation’s most blatantly political national holiday — created by the trade-union movement to celebrate the right of working people to bargain collectively and to stage strikes to press their demands. But no more, for good reason.

Even before Congress created the federal holiday in 1894, New York hosted the nation’s first Labor Day parade as 10,000 workers took off from their jobs to march from City Hall to Union Square. As the movement grew, so did the parades and celebrations.

How times have changed. Today, Labor...