Professor Marquis taught philosophy at the University of Kansas from 1967 until his retirement in 2014. He was, of course, best-known for his widely anthologized paper "Why Abortion is Immoral" (Journal of Philosophy, 1989), and he wrote widely in bioethics. I will add links to memorial notices as they appear. Comments are open for remembrances from those who knew Professor Marquis.
(Thanks to Dale Dorsey for the information.)