Eugene Power left Edwards Brothers in 1938 to start his own microfilming business, University Microfilm, Inc. (UMI) in 1938. In 1939, UMI filmed the Detroit News, the Detroit Free Press, and the Booth chain of newspapers using the best and latest equipment available. In 1940, it produced The American Periodical Series, which consisted of microfilm reproductions of all extant magazines published in the US from 1741-1799. Another series, consisting of writings about America from 1493 to 1800, followed that series. UMI also produced The American Culture Series, which was 69,000 pages long.

During World War II, UMI filmed and cataloged 6 million pages of rare/valuable books and manuscripts from various libraries and museums in England. In 1942, the US government contracted UMI to microfilm German scientific documents and other documents collected by British spies. This microfilming project resulted in the filming of over 13 million pages of Axis materials. After the war, UMI cataloged the collection. While at UMI, Power invented a ceiling projector which allowed the bedridden to more easily view microfilm. In 1948, UMI microfilmed The New York Times. Soon libraries began buying subscriptions to microfilm collections from UMI. In 1951, UMI gained the contract from ARL to microfilm Dissertations Abstracts. UMI was sold to Xerox in 1962, but Power continued to run it as a subsidiary of Xerox.