In the 1790s, the economy of the South was in decline. Demand for tobacco had dropped on the world market and production of the crop had depleted the soil in many tideland areas. This economic slump had reduced the importance of slaves and the institution appeared to be dying slowly. Other crops such as rice and Indigo also were less profitable given that subsidies from the mother country were no longer available after independence. Slaves had never been an important part of the economy of the North, where most of the states had either outlawed the practice or provided for gradual manumission. Congressional action in 1808 to end the slave trade provoked little protest, even from Southern sources. This picture was transformed through the activities of Eli Whitney, inventor of the cotton gin.