ERIE, Pennsylvania — Long before the furthest left corner of the Commonwealth began welcoming millions of sunbathers, Presque Isle State Park served as a critical shield for a young nation.

During the War of 1812, the peninsula’s natural, 5.8-square-mile harbor provided the perfect sanctuary. Master mariner Daniel Dobbins recognized that a shallow sandbar across the bay’s entrance would protect American shipbuilders from deep-draft British warships.