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.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.
More on grandfather clause from Infoplease:
See more Encyclopedia articles on: U.S. History