How did the federal government respond when former confederate states refused to ratify the fourteenth amendment

14th Amendment to the Constitution Was Ratified 
July 28, 1868 
On July 28, 1868, the 14th Amendment to the United States Constitution was ratified. The amendment grants citizenship to "all persons born or naturalized in the United States" which included former slaves who had just been freed after the Civil War. The amendment had been rejected by most Southern states but was ratified by the required three-fourths of the states. Known as the "Reconstruction Amendment," it forbids any state to deny any person "life, liberty or property, without due process of law" or to "deny to any person within its jurisdiction the equal protection of the laws."