If you’ve ever walked around Castle Island, you’ve probably noticed the tall granite obelisk standing just behind Fort Independence. It’s a monument honoring Donald McKay, one of the greatest shipbuilders of the 19th century and the man behind some of the fastest clipper ships ever built, including the legendary Flying Cloud. She was launched in 185 and known for setting the world sailing record from New York to San Francisco during the California Gold Rush.

Establishing his shipyard in East Boston in the 1840s, McKay quickly gained a reputation for building some of the fastest and most elegant clipper ships of the era. These ships, characterized by their sleek lines, tall masts, and large sails, were designed to maximize speed and efficiency, making them ideal for long-distance trade routes.

McKay’s shipyard in East Boston became a center of innovation and craftsmanship, attracting skilled workers from around the world. The shipyard’s success helped fuel East Boston’s growth as a maritime powerhouse, with numerous other shipyards and related industries sprouting up in the area.

While McKay built his famous ships across the harbor in East Boston, South Boston is home to one of the city’s most prominent tributes to him. The 52-foot granite obelisk at Castle Island was erected to recognize his incredible contributions to Boston’s maritime history and remains a favorite landmark for locals taking a walk around the fort.

Next time you’re grabbing a hot dog at Sully’s or strolling around Castle Island, take a minute to check it out. It’s a reminder of the shipbuilder whose work helped put Boston on the map—and whose legacy still stands tall in Southie today.