At the urging of labor activists in the late 19th century, Congress declared a national holiday on the first Monday in September to celebrate the hard workers of the United States. Now, 130 years later, Labor Day has become more widely known as a three-day weekend celebration that officially ends summer. And it's often seen as travelers' last chance to hit the open road, hop on a plane or book a staycation at a nearby hotel to grab one last dose of sunny R&R before the kids go back to school, the days grow shorter and pumpkin spice season begins.