Sean Gallagher, one of the founders of Say Yes to the Dress producer Half Yard Productions who spent over a decade at Discovery, died July 19 of cancer. He was 57..

Gallagher was heralded as a “pioneer” of reality television and a “kingmaker” as the industry took shape in its early years. Friends and colleagues including Warner Bros. Discovery boss David Zaslav and former A+E Networks CEO Nancy Dubuc paid tribute to Gallagher.

Gallagher founded Half Yard Productions in 2006 with Abby Greensfelder. In addition to TLC’s Say Yes to the Dress, the company made hundreds of hours of unscripted television including Bravo’s The Real Housewives of D.C., Animal Planet’s Hillbilly Handfishin’ and Discovery’s American Loggers and The Last Alaskans, Nat Geo’s Diggers and History’s How The States Got Their Shapes.

Before launching the Bethesda-based company, he spent over ten years working at Discovery. He started as an AP,...