Born in Lacon, Illinois on March 15, 1903, Thompson Marsh moved to Denver with his family in 1912 on account of his father's asthma. He received his BA (1924) and his JD (1927) from the University of Denver. He then received his LLM from Northwestern(1931), and his JSD from Yale (1935).
Professor Marsh was one of the most colorful and respected faculty members in the history of the University of Denver College of Law. He started at the University of Denver law school as the youngest professor in the country and retired 60 years later as the oldest. And on his retirement, he said, "I think I did just what I wanted to all my life."
Thompson's legal specialties and areas of emphasis at the University of Denver law school included property and mining law, future interests, legal philosophy, Hohfeldian analysis, and analytical jurisprudence.
He was demanding of himself and his students. His techniques sharpened student's analytical skills, and included the now infamous red, green, blue and black "technicolor" method of case analysis. He earned the recognition of his colleagues (1964 University Lecturer), the alumni (1978 Law Alumni Award, 1984 Evans Award), and the students (seven-time recipient of the Outstanding Faculty Award).
Other awards he received included: the Charles W. Delaney, Jr., Professor of Law award, 1971, Thompson G. Marsh Chair, 1978, Doctorate of Humane Letters Honorary Degree, University of Denver College of Law, 1987, Award of Merit, Colorado Bar Association, 1985, and Professor Emeritus, 1987.
Dean Emeritus Daniel S. Hoffman was quoted in his memorial: "Thompson above all thought disciplined thinking."
The New York Times, in reporting his death in 1992, emphasized that his classes influenced at least 4,000 lawyers who have practiced in and around the Denver area.
Although he loved teaching law, Thompson Marsh also found time to fill his life with many other interests. He was an expert bird-watcher, having a life-list of over 800 species. He was ranked first in Colorado and within the top 20 nationally, and was known to travel long distances on short notice to view a species he hadn't seen yet.
In addition to being an avid bird-watcher, Thompson Marsh had a love for mountaineering. In the course of his lifetime, he and his wife Susan climbed all 54 of Colorado's fourteen thousand foot peaks. He climbed his first fourteener, Mount Evans, before there was a road giving a clear way up it.
Thompson was also an amateur cellist and a lover of music. He and his wife, who played viola for years in the Denver Symphony Orchestra, formed a family chamber music group composed of the elder Marshes and their four daughters.
He also had a love of figure skating, which he often practiced with his wife on his backyard ice-rink.
He and his wife Susan were married in 1935, and they had four daughters, Nancy, Alice, Lucy, and Mary