The Grandfather Clause was enacted by seven southern states during and after the reconstruction era to prevent freedmen from voting. The clause, designed to negate the 15th Amendment to the U.S. Constitution which allowed black men to vote, significantly reduced African American political participation well into the 20th Century.  Starting in Louisiana in 1898 and working its way into laws and constitutions in seven other states by 1910, the Grandfather Clause stated that all men or lineal descendants of men who were voters before 1867 did not have to meet the educational, property, or tax requirements for voting then in existence. This effectively allowed all white males to vote while denying the franchise to black men and other men of color.  The Grandfather Clause, with its voting denial, became the centerpiece of a much larger system of discrimination and racial segregation.

The National Association for the Advancement of Colored People (NAACP), newly formed in 1909, mounted the first legal challenge to the Grandfather Clause.  It filed suit in Guinn v. United States, a case which reached the U.S. Supreme Court in 1915.  The Court ruled that Grandfather Clauses in Maryland and Oklahoma were null and void because they violated the Fifteenth Amendment to the U.S. Constitution.