In 1950, she started what would be a successful fight to integrate eating places in the District of Columbia. In the 1890s the District of Columbia had formalized segregation as did states in the South. Before then, local integration laws dating to the 1870s had required all eating-place proprietors "to serve any respectable, well-behaved person regardless of color, or face a $1,000 fine and forfeiture of their license." In 1949, Terrell and colleagues Clark F. King, Essie Thompson, and Arthur F. Elmer entered the segregated Thompson Restaurant. When refused Service, they promptly filed a lawsuit. Attorney Ringgold Hart, representing Thompson, argued on April 1, 1950, that the District laws were unconstitutional and later won the case against restaurant segregation. In the three years pending a decision in District of Columbia v. John R. Thompson Co., Terrell targeted other restaurants. Her tactics included boycotts, picketing, and sit-ins. Finally, on June 8, 1953, the court ruled that segregated eating places in Washington, DC, were unconstitutional.