Prior to ratification of the Fourteenth Amendment, the Civil Rights Act of 1866 was passed to

The Civil Rights Act of 1866, 14 Stat. 27-30, enacted April 9, 1866, was the first United States federal law to define citizenship and affirm that all citizens are equally protected by the law.[1] It was mainly intended to protect the civil rights of persons of African descent born in or brought to the U. S., in the wake of the American Civil War.[2] This legislation was enacted by Congress in 1865 but vetoed by President Andrew Johnson. In April 1866 Congress again passed the bill. Although Johnson again vetoed it, a two-thirds majority in each chamber overcame the veto and the bill therefore became law.

John Bingham and some other congressmen argued that Congress did not yet have sufficient constitutional power to enact this law. Following passage of the Fourteenth Amendment in 1868, Congress reenacted the 1866 Act in 1870