Ossian Sweet was a bell-hop in Detroit and an odd job man in Cleveland. However, after attending college and medical school at Ann Arbor, managed to qualify as a doctor. He also studied at the University of Vienna before moving back to Detroit where he established a surgery.

In 1925 Dr. Sweet had raised enough money to purchase a house in an middle-class area of the city. As soon as the neighbourhood heard that a black family intended to move into the area, they formed what they called an Improvement Association. At its first meeting they decided they would resort to violence if the Sweet family attempted to take possession of the house. When Dr. Sweet moved in he was accompanied by Henry Sweet, his bother and seven other men. They were all armed and when the house was attacked by a white mob, they opened fire, killing one man and seriously injuring another.

Charles Darrow, a man who specialized in defending unpopular causes, agreed to represent the men. In court he argued that Ossian Sweet had the right to use violence to defend his house against an attacking mob. The jury agreed, and the men were acquitted. As Darrow said in his autobiography: "The verdict meant simply that the doctrine that a man's house is his castle applied to the black man as well as to the white man."