The laws that supported discrimination based on race are primarily known as Jim Crow laws. These laws were enacted in the late 19th and early 20th centuries in the United States, particularly in Southern states, and they enforced racial segregation and discrimination against African Americans in various aspects of life, including education, housing, and public accommodations.
While the Dred Scott decision (Dred Scott v. Sandford, 1857) itself was a Supreme Court ruling rather than a law, it denied citizenship and constitutional rights to African Americans and upheld the legality of slavery, thereby legitimizing racial discrimination. However, it is more appropriate to refer to Jim Crow laws when discussing systematic, legalized racism in the United States.
Constitutional laws and common laws can also reflect historical frameworks that allowed discrimination, but they do not specifically represent a codified system of racial discrimination as explicitly as Jim Crow laws do.