Jim Crow laws enforced racial segregation and social inequality between blacks and whites from 1877 to the mid-1960s. Strict etiquette dictated that blacks were not allowed to make physical contact or show public affection with whites. Blacks had to use titles like Mr. and Mrs. when addressing whites but were referred to by their first names only. If in a car with whites, blacks were required to sit in the back. The Supreme Court declared racial segregation unconstitutional in 1954, but full enforcement of civil rights did not occur until the 1970s. Early civil rights acts passed in the 1860s-70s aimed to protect newly freed slaves' basic rights.