What made segregation illegal?

I think it was because racism was taken very seriously back in the day, people in the late 20th century 21st century are just now realizing that it's very rude and embarrassing, for example, being Hispanic or african american was taken as a threat, so if you one of those races/nationalities you were considering colored and like I said a threat so white people would ask you to move or leave the area you were in. but anyways back to the point, how segregation is now illegal.

Explanation:

i think since Martin Luther King Jr and Rosa parks made their statements by showing racism should not be aloud and Barack Obama being president has really affected the way whites treat African Americans and Hispanics, but I don't completely know so don't think everything I said was true, at least we have the internet.

you answered your own : -/