Because the Civil Rights Cases (1883) barred Congress from using the Fourteenth Amendment to reach private discrimination, Congress rested Title II of the 1964 Act on the Commerce Clause instead. The Court unanimously upheld it: because racial discrimination by hotels serving interstate travelers substantially burdened interstate commerce, Congress could prohibit it. Heart of Atlanta vindicated a generation of civil-rights legislative strategy and cemented the modern Commerce Clause's reach into civil rights.