With some sleight of hand involving a legal change to a gender-neutral name, they obtained a marriage license in another county, and in 1971, in white bell-bottom pantsuits and macramé headbands, they exchanged vows before a Methodist pastor and a dozen guests in a friend’s apartment. Their three-tiered wedding cake was topped by two plastic grooms, which a friend supplied by splitting two bride-and-groom figurines.

Ever since, they have maintained that theirs was the country’s first lawful same-sex wedding. The state and federal governments have yet to grant recognition, but the pastor, Roger W. Lynn, 76, calls theirs “one of my more successful marriages.”

“They are still happily married, and they love each other,” Mr. Lynn said.

The couple, now in their early 70s, spoke this month in a rare interview in the house they share here, nearly half a century after they joined their lives and earned a place in the history of gay rights, helping to make Minnesota an early center of gay activism.