Dred Scott vs Sanford:

In 1837 Dred Scott and enslaved African American, was traveling with is owner Dr. John Emerson. After spending much time in Illinois and Wisconsin, both free states, Emerson began hiring Scott out, which constituted as slavery and was illegal under the Missouri Compromise. After being left in Missouri, Illinois, and Wisconsin and the death of Emerson, Scott sued for his freedom in 1846.

The case went all the way to the Supreme Court, where they found that any person of African or African American descent was not to be considered a citizen of the United States, which meant that Scott was not able to bring suit in federal court.

This ruling was a step backwards in the fight for freedom and equality for African Americans. Although the ruling would later be rescinded by the 13th amendment, many were upset and horrified by the ruling.

Source: Horton, James Oliver, and Lois E. Horton. Slavery and the Making of America. New York: Oxford, 2006. 157-158.