Dred Scott was a slave owned by Peter Blow in Alabama. Scott moved with Blow when he moved to Missouri, another state that authorized slavery. After Blow died, his executor sold Scott to Dr. John Emerson, a St. Louis–based army doctor. Emerson then moved his family—and Scott—to Illinois, which was a free state. Emerson eventually moved back to St. Louis and died. Scott and his wife Harriet filed a lawsuit in Missouri courts, arguing that they were freed when Emerson had moved to the free state of Illinois. Emerson’s widow and her brother, John Sanford (court records misspelled his name as Sandford), contested Scott’s suit, leading to Scott v. Sandford case.