Complex sentence: He co-founded Washington University in St. Louis (initially called Eliot Seminary-much to his chagrin) in 1853, and served as its chancellor from 1870 to 1887, donating funds to its construction.
Split into simpler sentences: He co-founded Washington University in St. Louis (initially called Eliot Seminary-much to his chagrin) in 1853. He served as its chancellor from 1870 to 1887, and donated funds to its construction.