No doubt at least some of the island's wild horses arrived as victims of shipwrecks. Perhaps others were abandoned on the Outer Banks by the earliest explorers. The first European owners of Ocracoke, especially Richard Sanderson, used the island as grazing land for livestock (no fences were required). Early residents, William Howard and John Williams, brought more horses.
By the 19th century as many as three hundred wild ponies roamed the island. The annual July 4th pony penning was a major event in the early 20th century. Today, the National Park Service cares for a remnant herd of "wild" ponies in a large corral about 7 miles north of Ocracoke Village. You can read more here.
The Park Service also sponsors an Adopt-A-Pony program that is a popular way for folks to support the care and maintenance of out island's most popular residents.
Be sure to stop at the Pony Pen and pay a visit to some of the last descendants of Ocracoke's wild horses.
This month's Ocracoke Newsletter tells the delightful story of the 19th century "Stovepipe Hat" wreck. It has been told for years in books & magazines, but it probably never happened. You can read the story (and my research) here: http://www.villagecraftsmen.com/news062115.htm.