For decades, St. Thomas, Ontario, was a symbol of Canada-U.S. cooperation. In the 1960s, Ford opened a massive plant, rolling out Crown Victorias, Grand Marquis, and Town Car sedans. In 2011, as consumer demand shifted towards SUVs, the plant shut down. The town fought back and recently secured a $7-billion EV battery factory. But now, with trade tensions rising between Canada and the U.S., life looks uncertain for St. Thomas and its remaining autoworkers.