LIKE APPLE PIE, Paul Rudd movies and surreal Super Bowl commercials, the classic baseball cap is a beloved American institution—and not just for kids. “I’ve realized that in America, they’ve become the modern-day cowboy hat,” said Alex Wilcox, the British co-owner of bespoke clothier and tailoring shop Lord Willy’s in New York. And like the cowboy hat, Mr. Wilcox added, baseball caps connote masculinity, and give men of any age a stylish way to hide.
They’re also legitimately fashionable now. No longer just the province...