A controversy regarding single-sex education in the United States is its association with racist ideologies in the 1950s in the American South. After the "Brown v. Board of Education" (1954) ruled racial segregation in education unconstitutional, therefore paving the way to educating together black and white children, many conservatives reacted very negatively to the idea of black boys and white girls socializing together, potentially leading to interracial romantic couples. As such, segregation by sex in schools became quite common during that era across the Southern US, with many single sex educational institutions being established.