Complex sentence: Prior to 1965, the Bermuda school system was racially segregated and when the desegregation of schools was enacted in 1965, two of the formally maintained "white" schools and both single-sex schools opted to become private schools.
Split into simpler sentences: Prior to 1965, the Bermuda school system was racially segregated. When the desegregation of schools was enacted in 1965, two of the formally maintained "white" schools and both single-sex schools opted to become private schools.