An object has kinetic energy when itâs in motion. The amount of kinetic energy an object has depends on its mass and speed. Potential energy, on the other hand, is a stored energy when an object is at rest. It describes how much work the object could do if set into motion. Itâs an energy we can generally control. When an object is set into motion, its potential energy transforms into kinetic energy.
The Knights of Labor, the first national industrial union in the United States, was founded in Philadelphia on December 9, 1869, by Uriah Stephens (1821-82) and eight other Philadelphia garment cutters.
Though President Grover Cleveland declared Labor Day a national holiday in 1894, the occasion was first observed on Sept. 5, 1882, in New York City. A parade was organized by the city's Central Labor Union, a branch of the Noble Order of the Knights of Labor, a secretive labor union founded in 1869 by a clique of Philadelphia tailors.