What is one way Southern Democrats denied African Americans voting rights?

Disenfranchisement after the Reconstruction Era in the United States of America was based on a series of laws, new constitutions, and practices in the South that were deliberately used to prevent black citizens from registering to vote and voting. These measures were enacted by former Confederate states at the turn of the 20th century, and by Oklahoma upon statehood although not by the border slave states. Their actions defied the intent of the Fifteenth Amendment to the United States Constitution, ratified in 1870, which was intended to protect the suffrage of freedmen after the American Civil War.