Guinn v. United States(1915)
The so-called Grandfather Clause of the amendment to the constitution of Oklahoma of 1910 is void because it violates the Fifteenth Amendment to the Constitution of the United States.
The Grandfather Clause being unconstitutional, and not being separable from the remainder of the amendment to the constitution of Oklahoma of 1910, that amendment as a whole is invalid.
The Fifteenth Amendment does not, in a general sense, take from the States the power over suffrage possessed by the States from the beginning, but it does restrict the power of the United States or the States...
Edward White (Library of Congress)View Full Size