Labor Day became a national holiday after a bloody strike by railroad workers in Chicago.
Biden is conflicted about entering a Democratic race dominated thus far by Clinton, the party's favorite, and self-described socialist Bernie Sanders.
The president warned Republicans against shutting down the federal government over a budget dispute.
The executive order will benefit about 300,000 people working on government contracts.
Working too hard leads to strokes, diabetes and heart disease. Why are we killing ourselves?
A "Second Gilded Age" has brought levels of inequality not seen since labor unions first organized.