A map of the United States showing the effects of the Compromise of 1850. The map is keyed to show the free states and slave states, and notes California admitted to the Union as a free state; the Nebraska Territory as free by the Missouri Compromise Act of 1820, opened to slavery by the Kansas-Nebraska Act of 1854, and opened to slavery by the Dred Scott Decision of 1857; the Oregon Territory free by the Act of 1848, opened to slavery by the Dred Scott Decision of 1857; the Utah and New Mexico territories free by Mexican law, opened to slavery by the Compromise Act of 1850 and by the Dred Scott Decision of 1857; and the Missouri Compromise Line.