The lead plaintiffs in Illinois’ same-sex marriage lawsuit have finally married, after 51 years together.

Patrick Bova and Jim Darby were part of a series of lawsuits that lead a judge in February to rule that the state’s ban on same-sex couples marrying was unconstitutional.

Following that ruling same-sex marriage began in 16 Illinois counties, with the remaining 86 joining on Sunday, after same-sex marriage legislation came into effect.

Darby, 81, was born in Chicago, and worked as a dock worker before serving in the Navy during the Korean war.

After receiving an honourable discharge from the military, he met Patrick Bova, 76, when they both attended the University of Chicago in 1963.

The pair have been together ever since, and have campaigned relentlessly on veterans’ and gay rights issues.

They finally married yesterday at Chicago’s Museum of Contemporary Art, at a ceremony attended by the state’s governor Pat Quinn.

In a tribute to the pair, Camilla Taylor of Lambda Legal wrote: “What a joyous day! Jim and Patrick have waited for decades to marry each other.

“Always together and always sharing a joke or a smile, Jim and Patrick are examples of how nurturing and strong love can be.

“They’ve marched together in countless parades and engaged in peaceful protests to end discrimination against lesbians and gay men in the military, and then became lead plaintiffs in our lawsuit for the freedom to marry.

“Not only did they fight for justice at home, Jim also fought for his country abroad – he is a proud Korean War veteran. I’m thrilled to have witnessed the day when our government finally granted him the dignity and respect of allowing him to marry the love of his life.

“Jim and Patrick reflect the best our nation has to offer, and they are wonderful role models not just for gay and lesbian youth, but for all of us. I’m honoured to know them and toast their great American love story.”