Complex sentence: During a hurricane in 1749, the Chesapeake Bay rose above normal, sand spit was washed up at Sewell's Point and, with the help of The Great Coastal Hurricane of 1806, Willoughby Spit was formed.
Split into simpler sentences: During a hurricane in 1749, the Chesapeake Bay rose above normal, and a sand spit was washed up at Sewell's Point. With the help of the Great Coastal Hurricane of 1806, Willoughby Spit was formed.