in U.S. law, the constitutional guarantee that no person or group will be denied such protection under the law as is enjoyed by similar persons or groups
i.
e., persons similarly situated must be treated similarly. The 14th Amendment to the Constitution of the United States prohibits states from denying any person "the equal protection of the laws." Until the mid-20th century the requirement was applied minimally
except in some cases of racial discrimination, such as the use of literacy tests and grandfather clause s to restrict the voting rights of blacks. In Plessy v. Ferguson (1896), the Supreme Court of the United States upheld "separate but equal" facilities for the races, thus sanctioning racial segregation. Beginning in the 1960s, the court under Chief Justice zoning , municipal services, and school financing. During the tenure of Chief Justices {{link=Burger, Warren Earl">Warren E. Burger and William H. Rehnquist , the court continued to add to the types of cases that might be adjudicated under equal protection, including cases involving sexual discrimination, the status and rights of aliens, abortion rights, and access to the courts.