Ezra Bucknam b. 1806 in Columbia< Maine, was a successful shipwright, having left home for New York City at the age of 14. He invented and built the screw docks at Winter Street and later moved them to the new docks at South Street, where he carried on business until 1867, retired and left the business to his son and nephew. He also was the US Government Inspector of Harbors and Docks. A son was also named Ezra, but lived only to the age of 9. "The 1850 U.S. Census for Ward 7 of New York city lists him as a Shipwright with an property value of $14,000 (M432. Roll 540, p. 388)
He died in 1870 in Haiti, Santa Domingo.I have other information of his family, who also lived in NY City, if you are interested.E-mail me if you wish.