The Decker Building—periodically referred to as the Union Building—is located at 33 Union Square West in Manhattan, New York City. Built in 1892 for the Decker Brothers piano company according to designs by the radical anarchist architect John H. Edelmann, working out of the offices of Alfred Zucker, it replaced the earlier Decker Building on the same lot, designed by Leopold Eidlitz and built in 1869. Andy Warhol had his Factory on the sixth floor of this building from 1968 through 1973. It is also where Valerie Solanas shot Warhol and art critic and curator Mario Amaya in 1968.