Legions of African-American lawyers affiliated with the National Bar Association ushered in the rule of law through the turbulent 1920s and 1930s, R.D. Evans, for example, who later became a member of the National Bar Association, tried the first case in Waco, Texas, to prevent the Democratic Party from forbidding "colored people" to vote in election primaries in 1919. From the 1920s through the 1950s, African-American lawyers such as the Honorable James A. Cobb, T. Gillis Nutter, and Ashbie Hawkins fought the famous segregation case of Louisville, and the Covenants case of The District of Columbia. Early National Bar Association pioneers S.D. McGill, R.P. Crawford, and J.L. Lewis fought to have sentences of execution stayed in the Florida case popularly referred to as the "Four Pompano Boys." Wherever there was a fight to wage in defense of the rights of Blacks and poor people, the NBA was there.
When the number of African-American lawyers barely exceeded 1,000 nationwide, the National Bar Association attempted to establish "free legal clinics in all cities with a colored population of 5,000 or more." The National Bar Association was ahead of the "War on Poverty" programs of the 1960s, which gave birth to federal legal aid to the indigent. Members of the National Bar Association were leaders of the pro bono movement at a time when they could least afford to provide free legal services and before poverty law became profitable. When the Supreme Court outlawed school segregation in Brown v. Board of Education, the National Bar Association was only 25 years old. This decision culminated a long struggle by African-American lawyers. Thurgood Marshall, the first African-American United States Supreme Court Justice, and United States District court Judge Constance Baker Motley, the first African-American female federal judge, are two outstanding jurists who helped make Brown v. Board of Education a pivotal case in American Civil Rights history. Through continuing service, the National Bar Association has become known as America's legal conscience.