Answer:
Jim Crow laws were designed to enforce this doctrine by requiring racial segregation for public facilities.
Explanation:
The "separate but equal" doctrine was established by the Supreme Court case Plessy vs. Ferguson. This case stated that separate but equal facilities for black and whites did not violate the constitution.
Jim Crow laws helped to enforce this idea by creating separate facilities for blacks and whites. These facilities included public bathrooms, parks, schools, restrooms, etc. These types of laws would exist in the US for roughly 6 decades before they were deemed unconstitutional.