TOKYO—For the first time in more than a century, Britain claimed a relay gold at the Olympic pool. The United States, shockingly, didn’t even make the podium. A dynamic quartet carried the British to a dominating victory in the men’s 4×200-meter freestyle relay Wednesday. Tom Dean, the 200 free gold medalist led off and 200 silver medalist Duncan Scott swam the anchor leg. James Guy—now a three-time Olympic medalist—and 18-year-old Matthew Richards took the middle legs. “This has been years in the making,” Dean said. “We’ve been getting stronger and stronger.” The British just missed the world record with a winning time of 6 minutes, 58.58 seconds. The Americans set the record at 6:58.55 in rubberized suits at the 2009 world championships in Rome. “We were so close to the world record in the end,” Scott said. “If anything, I’m a bit gutted.” Imagine how the Americans must’ve been feeling. …