Edward Sagarin (September 18, 1913 – June 10, 1986), also known by his pen name Donald Webster Cory, was an American professor of sociology and criminology at the City University of New York, and a writer. His book The Homosexual in America: A Subjective Approach, published in 1951, was considered "one of the most influential works in the history of the gay rights movement", and inspired compassion in others by highlighting the difficulties faced by homosexuals.

He was titled "father of the homophile movement" for asserting that gay men and lesbians deserved civil rights as members of a large, unrecognised minority. However, Vern L. Bullough believes the title is undeserved as Sagarin did not actively participate in resistance and did not join any homophile organisations until 1962, a time when he was seeking a topic to analyse in his thesis.

Sagarin was born in Schenectady, New York, to Russian Jewish parents. Sagarin was born with scoliosis, which produced a hump on his back. He attended high school and, after graduating, spent a year in France where he met André Gide. Upon his return to New York, he enrolled at City College of New York, but was forced to drop out of college due to the Great Depression.

In 1934, Sagarin met Gertrude Liphshitz, a woman who shared his left-wing political interests. They married in 1936 and soon after, Gertrude gave birth to a boy. Sagarin established himself in the perfume and cosmetics industry, becoming knowledgeable about the chemistry of perfumes, and publishing The Science and Art of Perfumery in 1945.

Sagarin began a dual life, publishing The Homosexual in America: A Subjective Approach in 1951, which was deemed an "act of heroism", under the pseudonym of Donald Webster Cory. The use of the pen name, and the attitudes that differed when Sagarin used either of his identities, led to the comparison of Sagarin/Cory to the Dr. Jekyll/Mr Hyde character. Mr. Cory, who presented homosexuals as a despised minority, was seen as a "mythic hero", where Dr. Sagarin (as he would later be known) was a "hunchback deviant".

The publication of the book was considered a "radical step", as it was the first publication in the United States that discussed homosexual politics and sympathetically presented the plight of homosexuals. Sagarin described how homosexuals were discriminated against in almost all aspects of their lives and called for a repeal of anti-homosexuality laws;

One great gap separates the homosexual minority from all others, and that is its lack of recognition, its lack of respectability in the eyes of the public, and even in the most advanced circles.

A research report by Alfred Kinsey et al., Sexual Behavior in the Human Male (1948), had a beneficial effect on the reception of Sagarin's publication. In 1952, due to the success of The Homosexual in America: A Subjective Approach, Sagarin established a subscription book service called "Cory Book Service", which chose a gay-themed literary work each month. The Cory Book Service played a fundamental role in sparking the gay-rights movement in the US and helped other organizations such as the Mattachine Society and ONE magazine grow. It would change ownership multiple times and would send out recommendations of queer literature for 17 years.