Legal challenges to disfranchisement.

Although African Americans quickly began legal challenges to such provisions in the 19th century, it was years before any were successful before the U.S. Supreme Court. Booker T Washington, better known for his public stance of trying to work within societal constraints of the period at Tuskegee University, secretly helped fund and arrange representation for numerous legal challenges to disfranchisement. He called upon wealthy Northern allies and philanthropists to raise funds for the cause. The Supreme Court's upholding of Mississippi's new constitution, in Williams v Mississippi (1898), encouraged other states to follow the Mississippi plan of disenfranchisement. African Americans brought other legal challenges, as in Giles v Harris (1903) and Giles v Teasley (1904), but the Supreme Court upheld Alabama constitutional provisions. In 1915, Oklahoma was the last state to append a grandfather clause to its literacy requirement due to Supreme Court cases.

From early in the 20th century, the newly established National Association for the Advancement of Colored People (NAACP) took the lead in organizing or supporting legal challenges to segregation and disfranchisement. Gradually they planned the strategy of which cases to take forward. In Guinn v United States (1915), the first case in which the NAACP filed a brief, the Supreme Court struck down the grandfather clause in Oklahoma and Maryland. Other states in which it was used had to retract their legislation as well. The challenge was successful.

But, nearly as rapidly as the Supreme Court determined a specific provision was unconstitutional, state legislatures developed new statutes to continue disenfranchisement. For instance, in Smith v Allwright (1944), the Supreme Court struck down the use of state-sanctioned all-white primaries by the Democratic Party in the South. States developed new restrictions on black voting; Alabama passed a law giving county registrars more authority as to which questions they asked applicants in comprehension or literacy tests. The NAACP continued with steady progress in legal challenges to disenfranchisement and segregation.

In 1957, Congress passed the Civil Rights Act of 1957 to implement the Fifteenth Amendment. It established the United States Civil Rights Commission; among its duties is to investigate voter discrimination.

As late as 1962, programs such as Operation Eagle Eye in Arizona attempted to stymie minority voting through literacy tests. The Twenty-fourth Amendment was ratified in 1964 to prohibit poll taxes as a condition of voter registration and voting in federal elections. Many states continued to use them in state elections as a means of reducing the number of voters.