Emir of Kano with cavalry, 1911King Duke IX of 287x287pxElizabethII|leftA changing legal imperative (the transatlantic slave trade was outlawed by Britain in 1807) and economic imperative (a desire for political and social stability) led most European powers to support the widespread cultivation of agricultural products, such as the palm, for use in European industry. The Atlantic slave trade was engaged in by European companies until it was outlawed in 1807. After that illegal smugglers purchased slaves along the coast by native slavers. Britain's West Africa Squadron sought to intercept the smugglers at sea. The rescued slaves were taken to Freetown, a colony in West Africa originally established by Lieutenant John Clarkson for the resettlement of slaves freed by Britain in North America after the American Revolutionary War.