Theodosius Fowler Secor was an American marine engineer. Secor co-founded T. F. Secor & Co. in New York in 1838, which was one of the leading American marine engineering facilities of its day. In 1850, he sold his stake in the company to his erstwhile partner, Charles Morgan, in order to go into partnership with Cornelius Vanderbilt in the purchase of another leading New York marine engineering facility, the Allaire Iron Works.

The Morgan Iron Works was a 19th-century manufacturing plant for marine steam engines located in New York City, United States. Founded as T. F. Secor & Co. in 1838, the plant was later taken over and renamed by one of its original investors, Charles Morgan.