They enforced compulsory segregation of people along racial lines so African Americans couldn't swim in the same swimming pools as whites.
People of Native American descent were denied a public education and in many cases forced to attend boarding schools to wipe out any trace of Native American heritage.
It resulted in the "separate but equal" policy that was eventually ruled unconstitutional.
The policies aimed at African Americans are probably more well known. But the policies aimed at Native Americans should not be overlooked either. The the U.S. government pushed many thousands of Native American children to attend “assimilation” boarding schools in the late 19th century. Boarding schools followed early history of attempts to kill or remove Native Americans. The new method was to try to teach them to be more like white people. So these were "segregation" laws in sort of a reverse direction, trying to make it impossible to remain a Native American and become like a "proper" American.
