From Wikipedia :
Voltamp was an early American manufacturer of toy trains based in Baltimore, Maryland. Founded by Manes Fuld (1863–1929), the son of a Baltimore stove dealer, Voltamp's trains utilized the same 2-inch gauge metal track as Carlisle & Finch, the inventor of the electric toy train. It is significant for its 1907 release of the first electric toy train that operated on household alternating current; earlier electric trains had used battery power.
Voltamp released its first toy train product in 1903.
Although Voltamp outlasted Carlisle & Finch, its primary competitor, both companies were eclipsed in the marketplace by the Ives Manufacturing Company and Lionel Corporation, and Voltamp exited the market in 1922, selling its line to Boucher.