Fourteenth Amendment, Section 5:

The Congress shall have the power to enforce, by appropriate legislation, the provisions of this article.

In the aftermath of the Civil War, Congress, in addition to proposing to the states the Thirteenth, Fourteenth, and Fifteenth Amendments, enacted seven statutes designed in a variety of ways to implement the provisions of these Amendments.¹ Several of these laws were general civil rights statutes that broadly attacked racial and other discrimination on the part of private individuals and groups as well as by the states, but the Supreme Court declared unconstitutional or rendered ineffective practically all of these laws over the course of several years.² In the end, Reconstruction was abandoned and with rare exceptions no cases were brought under the remaining statutes until fairly recently.³ Beginning with the Civil Rights Act of 1957, however, Congress generally acted pursuant to its powers under the Commerce Clause⁴ until Supreme Court decisions indicated an expansive concept of congressional power under the Civil War amendments,⁵ which culminated in broad provisions against private interference with civil rights in the 1968 legislation.⁶

constitution.congress.gov