In June 2015, the Supreme Court made same-sex marriage the law in all fifty states in a decision as groundbreaking as Roe v Wade. At the heart of the Obergefell v Hodges case is a story of law and love – and a promise made to a dying man who wanted to know how he would be remembered. Twenty years ago, Jim Obergefell and John Arthur fell in love in Cincinnati, Ohio, a place where gays were routinely picked up by police and fired from their jobs. In 2013, the Supreme Court ruled that the federal government had to provide married gay couples all the benefits offered to straight couples. Jim and John – who was dying of the crippling neurodegenerative disease, Amyotrophic Lateral Sclerosis (ALS) – flew to Maryland, where same-sex marriage was legal. But back home, Ohio refused to recognise their union, or even list Jim’s name on John’s death certificate. Then they met Al Gerhardstein, a courageous small-town attorney who had spent nearly three decades advocating for civil rights and who now saw an opening for the cause that few others had before him. Against overwhelming odds, this grieving man and his nuggety lawyer introduced the most important gay rights case in US history and won a David and Goliath battle that inspired the rest of the world.