Professor Ritchie retired in 1992. His current interests include Theoretical Physics, Computing (CAD, cartography, and Quantum Mechanics computations), and Ancient History. He currently resides in Florida and is wring a World History Atlas for use on PCs.

Professor Ritchie's researches in the area of solvent and structural effects on rates and equilibria of organic reactions were described in ca. 80 publications, more of them in J. Am. Chem. Soc., over his 31 years at UB. He was also the author of the text Physical Organic Chemistry, The Fundamental Concepts, which appears in two editions, the latest in 1990. In 1970, Professor Ritchie received the Jacob F. Schoellkopf Medal of the Western New York ACS for his contributions to understanding factors influencing kinetic and equilibrium acidities of carbon acids.