Slaughter-House Cases and United States v. Darby Lumber Co. did not both involve civil rights law.
 It was a pivotal case in early civil rights law and held that the Fourteenth Amendment protects the privileges or immunities of citizenship of the United States, not privileges and immunities of citizenship of a state. 
United States v. Darby Lumber Co., 312 U.S. 100 (1941) , was a case in which the United States Supreme Court upheld the Fair Labor Standards Act of 1938, holding that the U.S. Congress had the power under the Commerce Clause to regulate employment conditions. 
