It was more or less an all-white miss American from 1921 to 1970 with a few exceptions...
Rule #7: contestants must be of good health and
of the white race" - that rule was in effect till the 1950 and people had to prove that their lineage had no black ancestry. The first black contestant was in 1970. Surprisingly the first Asian contestant was from Hawaii back in 1948 and the first Jewish contestant won it all in 1945 although she was pressured to change her name to something less Jewish and she refused. After she won the tourney, 5 pageant sponsors withdrew from having her represent their company as the Miss America representative.
But yes please pretend history of institutionalized racism wasn't part of the USA's past...