Founded in Baltimore, Maryland, in 1892, the Crown Cork & Seal Company was created to manufacture the ”crown cork” — a revolutionary metal bottle cap invented in the city by William Painter and one of the world’s first mass-produced disposable products. The invention was immensely successful; by the 1920s, the company was supplying half the world’s bottle caps, producing billions annually. Its factory became one of the largest manufacturing plants in the United States — a city within a city.