Diana Cephas was the plaintiff in a freedom suit filed in St. Louis, Missouri in 1840. She won her case after it went to trial in the Circuit Court of St. Louis County in 1843. Born into slavery in Maryland, she and her young son Josiah had been taken to the free state of Illinois in 1839, where she was hired out by her slaveholder over several months. She was then taken to Missouri, a slave state, but won her freedom with the help of freedom suit attorney Francis B. Murdoch, despite the efforts of lawyers Myron Leslie and Roswell M. Field to discredit her.