largest slave revolt in American history, the German Coast Uprising, took place in the Orleans Territory. Between 64 and 500 slaves rose up on the "German Coast," forty miles upriver of New Orleans, and marched to within of the city gates. All of the limited number of U.S. troops were gathered to suppress the revolt, as well as citizen militias. U.S. statehood Louisiana became a U.S. state on April 30, 1812. The western boundary of Louisiana with Spanish Texas remained in dispute until the Adams-Onís Treaty of 1819, which was formally ratified in 1821, The area referred to as the Sabine Free State served as a neutral buffer zone. With the growth of settlement in the Midwest (formerly the Northwest Territory) and Deep South during the early decades of the 19th century, trade and shipping increased markedly in New Orleans. Produce and products moved out of the Midwest down the Mississippi River for shipment overseas, and international ships docked at New Orleans with imports to send into the interior. The port was crowded with steamboats, flatboats, and sailing ships, and workers speaking languages from many nations. New Orleans was the major port for the export of cotton and sugar. The city's population grew and the region became quite wealthy. More than the rest of the Deep South, it attracted immigrants for the many jobs in the city. The richest citizens imported fine goods of wine, furnishings, and fabrics. By 1840 New Orleans had the biggest slave market in the United States, which contributed greatly to the economy. It had become one of the wealthiest cities and the third-largest city in the nation. The ban on importation of slaves had increased demand in the domestic market. During these decades after the American Revolutionary War, more than one million enslaved African Americans underwent forced migration from the Upper South to the Deep South, two thirds of them in the slave trade. Others were transported by slaveholders as they moved west for new lands. With changing agriculture in the Upper South as planters shifted from tobacco to less labor-intensive mixed agriculture, planters had excess laborers. Many sold slaves to traders to take to the Deep South. Slaves were driven by traders overland from the Upper South or transported to New Orleans and other coastal markets by ship in the coastwise slave trade. After sales in New Orleans, steamboats operating on the Mississippi transported