The sawing off of Manhattan Island is an ancient New York City story that is largely unverified. It describes a practical joke allegedly perpetuated in 1824 by a retired ship carpenter named Lozier . According to the story, in the 1820s a rumor began circulating among city merchants that southern Manhattan Island was sinking near the Battery due to the weight of the urban district. It was believed that by cutting the island, towing it out, rotating it 180 degrees, and putting it back in place that Manhattan would be stabilized, and that the thin part of the island could be condemned. Surprisingly the main concern was not the futility of the idea but of Long Island being in the way. Lozier finally assembled a large workforce and logistical support. At a massive groundbreaking ceremony, Lozier did not show up but hid in Brooklyn and did not return for months.

The story did not appear in any known newspapers, though the press characteristically did not report on such pranks in that era. The hoax was first documented in Thomas F. De Voe 's 1862 volume The Market Book, and was told again in Herbert Asbury's 1934 title All Around The Town .