On Nov. 13, 1856, witnesses on San Francisco’s shoreline were astonished by the sight of a pregnant 19-year-old girl guiding a grand, 216-foot-long clipper ship into port. Mary Ann Patten had spent the previous two months leading the crew and cargo of the Neptune’s Car to safety from Chile’s Cape Horn. That Mary had successfully overseen the ship’s safe passage — even while nursing her ailing husband — made her an instant celebrity. That she was the first American woman to captain a merchant vessel made her a nautical legend.