In 1890, The Mississippi Constitutional Convention began systematic exclusion of Blacks from  politics in the  South.

The Mississippi Plan (Literacy and “understanding tests”) lasted until November 1st of that year and was later adopted with embellishments by other states: South Carolina (1895), Louisiana (1898), North Carolina (1900), Alabama (1901), Virginia (1901), Georgia (1908), and Oklahoma (1910). Southern states later used “White primaries” and other devices to exclude Black voters.

Once whites regained control of the state legislatures using these tactics, a process known as “Redemption,” they used gerrymandering of election districts to further reduce Black voting strength and minimize the number of black elected officials. In the 1890s, these states began to amend their constitutions and to enact a series of laws intended to re- establish and entrench white political supremacy.

Reference:
The Encyclopedia of African-American Heritage
by Susan Altman
Copyright 1997, Facts on File, Inc. New York
ISBN 0-8160-3289-0