Evan Wolfson is an attorney and gay rights advocate. He is the founder of Freedom to Marry, a group favoring same-sex marriage in the United States, serving as president until its 2015 victory and subsequent wind-down. Wolfson authored the book Why Marriage Matters: America, Equality, and Gay People's Right to Marry, which Time Out New York magazine called, "Perhaps the most important gay-marriage primer ever written". He was listed as one of Time magazine's 100 most influential people in the world. He has taught as an adjunct professor at Columbia Law School, Rutgers Law School, and Whittier Law School and argued before the Supreme Court in Boy Scouts of America v. Dale. He now teaches law and social change at Georgetown Law School and at Yale University; serves as a senior counsel at Dentons, the world's largest law firm; and primarily provides advice and assistance to other organizations and causes, in the United States and globally, that are seeking to adapt the lessons on "how to win" from the same-sex marriage movement.

Boy Scouts of America et al. v. Dale, 530 U.S. 640 (2000), was a landmark decision of the US Supreme Court, decided on June 28, 2000, that held that the constitutional right to freedom of association allowed the Boy Scouts of America (BSA) to exclude a homosexual person from membership in spite of a state law requiring equal treatment of homosexuals in public accommodations. More generally, the court ruled that a private organization such as the BSA may exclude a person from membership when "the presence of that person affects in a significant way the group's ability to advocate public or private viewpoints". In a 5-4 decision, the Supreme Court ruled that opposition to homosexuality is part of BSA's "expressive message" and that allowing homosexuals as adult leaders would interfere with that message.