In 1820 the U. S. Congress passed the Missouri Compromise which admitted Maine to the Union as a free state, Missouri as a slave state, and made Missouri’s southern border, the 36 degrees 30 minutes parallel, the boundary north of which slavery would not be allowed within the Louisiana Purchase. Dred Scott was born a slave in Virginia sometime in the late 18th or early 19th century. In 1830, his owner moved to Missouri (a slave state) and brought Dred Scott with him. In 1833 Scott was sold to an army surgeon, Dr. John Emerson, who later moved first to Illinois (a free state) and then to Wisconsin Territory, and both times he took Dred Scott with him. Emerson returned with Scott to Missouri in 1838. Scott thus had been held as a slave in a free state and then in an area where slavery was outlawed by the Missouri Compromise. Emerson died in 1843 and in his will left Scott to his widow, the former Irene Sanford whose brother was the executor of Emerson’s will. In 1846, Dred Scott and his wife Harriet filed a petition in a Missouri court requesting permission to file suit in order to establish their right to be freed since they had resided on free soil. After two trials and the Scotts temporarily winning their freedom, the Missouri Supreme Court in 1852 reversed the lower court’s verdict and held that it would not enforce the antislavery laws of other states and that the Scotts’ residence on free soil had not changed their status as slaves. The Scotts then brought suit in a U.S. Circuit Court where the verdict once more was that they were still slaves. The case was now appealed to the U.S. Supreme Court where it was argued in early 1856 and then reargued in late 1856.