Final answer:
After the Civil Rights Act was passed, the federal government overrode President Johnson's veto, making it the first act passed over a veto. The Act established the citizenship of African Americans and allowed the federal government to intervene in state affairs to protect citizens' rights.
Step-by-step explanation:
After Congress passed the Civil Rights Act in April 1866, the federal government took several actions. First, President Johnson vetoed the Civil Rights Act, but his veto was overridden by Congress. This marked the first act passed over a Presidential veto. Additionally, the passing of the Civil Rights Act foreshadowed the provisions of the Fourteenth Amendment, as it established the citizenship of African Americans and gave the federal government the right to intervene in state affairs to protect citizens' rights.