Youngest brother to Frank Eldred Legg and Victor Eldred Legg, also of Ann Arbor, MI.
He trained as a landscape architect at the University of Michigan at Ann Arbor and from 1935 was professor of landscape architecture at Oregon State College, but moved back to Michigan in the 1940s to care for his parents.
In 1949 he moved to Los Angeles with his partner Merton Bird. In 1950 the couple founded The Knights of the Clock, a support group for inter-racial gay couples. The couple actively joined the national Mattachine Society, but W. Dorr Legg later led a split to form the influential ONE, Inc.. As publisher of the organization's journal, Legg was forced to sue the United States Postal Service to defend its right to be distributed through the US Mail. The case was pursued through appeals to a successful conclusion in 1958 before the US Supreme Court. W. Dorr Legg travelled to Germany in the 1950s to recover the remains of the archives of the Institut für Sexualwissenschaft.
Dorr Legg continued working tirelessly for gay rights until his death, and in the early 1990s published his magnum opus, Homophile Studies in Theory and Practice. He had previously published such groundbreaking books as Homosexuals Today and A Manual for Peer Counseling of Homosexuals, and otherwise contributed immeasurably to the development of gay rights in the USA.
Cutler, Marvin (pseud of W. Dorr Legg). Homosexuals Today: 1956 Handbook of Organizations and Publications. ONE, Inc., Los Angeles, CA 1956.
Legg, W. Dorr, David G. Cameron, Walter L. Williams and Donald C. Paul. "Homophile Studies in Theory and Practice." ONE Institute Press, Los Angeles, CA and GLB Publishers, San Francisco, CA, 1994.
Bullough, Vern L., W. Dorr Legg, Barrett W. Elcano, James Kepner. "An annotated bibliography of homosexuality." The Institute for the Study of Human Resources, Los Angeles & Garland Publishing, Inc., New York & London, 1976.
Bullough, Vern L. Before Stonewall: Activists for Gay and Lesbian Rights in Historical Context. Harrington Park Press, 2002.