Washington, D. C. - This Act amended the Civil Rights Act of 1870. It made it a crime to stop Black Americans from being registered to vote. It put National elections under the control of the Federal government. Voters for elected officials for Federal(not State) office were protected under Federal law.
This was the Second Enforcement Act of the Fifteenth Amendment.
Washington, D. C. - The Civil Rights Act of 1871, was the third (and final) enforcement act of the Reconstruction Era. It was to enforce the Fourteenth Amendment.
This act was meant to stop the Ku Klux Klan, White League, and other white supremacists. They attacked duly elected officers of the United States. This act made it a crime that included fines, jail time, and possible civil action.
None of the enforcement acts were ever used to protect Black Americans, despite their intent. The United States Supreme Court stopped any chance of that in the case of United States v. Cruikshank.