In 1916 Congress made its first effort to control child labour by passing the Keating-Owen Act. The legislation forbade the transportation among states of products of factories, shops or canneries employing children under 14 years of age, of mines employing children under 16 years of age, and the products of any of these employing children under 16 who worked at night or more than eight hours a day. In 1918 the Supreme Court ruled that the Keating-Owen Act was unconstitutional.