grandfather clause, provision in constitutions (adopted 1895-1910) of seven post-Reconstruction Southern states that exempted those persons who had been eligible to vote on Jan. 1, 1867, and their descendants from rigid economic and literacy requirements for voting. Since African Americans had not yet been enfranchised on that date, the provision effectively barred them from the polls while granting voting rights to poor and illiterate whites. Such provisions were ruled unconstitutional by the Supreme Court in 1915. The term grandfather clause is now applied to any kind of legal exemption based on prior status.

Constitutional provision enacted by seven Southern U.S. states (1895–1910) to deny suffrage to African American men. It exempted descendants of men who voted before 1867 from meeting new literacy and property requirements. Since African American men were not granted voting rights until passage of the 15th Amendment in 1870, this clause effectively prevented them, and many impoverished and illiterate whites, from voting. The U.S. Supreme Court declared such clauses unconstitutional in 1915.

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