A map of the United States in 1821 showing the results of the Missouri Compromise of 1820 over the issue of prohibition of slavery. The map is coded to show the areas of the Free States, the Slave States, the Michigan Territory as Free by the Ordinance of 1787, the portion of the Missouri Territory that allowed slavery, the remainder of the Louisiana Purchase (Missouri Territory) north of 36 degrees 30' Free by the Missouri Compromise, the Arkansas Territory open to slavery, and Florida open to slavery.