The right of same-sex couples to marry provoked decades of intense conflict before it was upheld by the U.S. Supreme Court in 2015. Yet some of the most divisive contests shaping the quest for marriage equality occurred not on the culture-war front lines but within the ranks of LGBTQ advocates. Nathaniel Frank tells the dramatic story of how an idea that once seemed unfathomable--and for many gays and lesbians undesirable--became a legal and moral right in just half a century.

Awakening begins in the 1950s, when millions of gays and lesbians were afraid to come out, let alone...