Complex sentence: Barnard College was Columbia University's women's liberal arts undergraduate college until its all-male coordinate school Columbia College went co-ed in 1983; to this day, Barnard continues to be an all-women's undergraduate college affiliated with Columbia.
Split into simpler sentences: Barnard College was Columbia University's women's liberal arts undergraduate college until its all-male coordinate school Columbia College went co-ed in 1983. To this day, Barnard continues to be an all-women's undergraduate college affiliated with Columbia.