In 1790, about 3,000 bales of cotton were produced in America each year. A bale was equal to about 500 pounds. By 1801, with the spread of the cotton gin, cotton production grew to 100 thousand bales a year. After the destructions of the War of 1812, production reached 400 thousand bales a year. As America was expanding through the land acquired in the Louisiana Purchase of 1803, yearly production exploded to four million bales. Cotton was king. It exceeded the value of all other American products combined, about three fifths of America's economic output. But instead of reducing the need for labor, the cotton gin propelled it, as more slaves were needed to plant and harvest king cotton. The cotton gin and the demand of Northern and English factories re-charted the course of American slavery. In 1790, America's first official census counted nearly 700 thousand slaves. By 1810, two years after the slave trade was banned in America, the number had shot up to more than one million. During the next 50 years, that number exploded to nearly four million slaves in 1860, the eve of the Civil War.