Thomas Kennard Thomson (April 25, 1864 - July 1, 1952) was a New York City based civil engineer active in the first half of the 20th century. Thomson was born in Buffalo, New York, the son of William Alexander Thomson (1816 - 1878), founder and builder of the Canada Southern Railroad. He studied at the University of Toronto, graduating in 1886, then returning for a degree in Civil Engineering and a Doctorate of Science. He initially worked in Canada, first on the Canadian Pacific Railroad in the Rocky Mountains, then with the Dominion Bridge Company in Montreal. He moved to Brooklyn, New York, in 1889, initially taking a position with Pencoyd Bridge Company of Pennsylvania. He left this position within a year to attend the Paris Exhibition with the American Society of Civil Engineers. Thomson returned to a long and successful engineering career, working on hundreds of major projects, including more than 50 skyscrapers and 200 bridges. His New York City projects included the Singer Building (149 Broadway), the Commercial Cable Building (22-24 Broad Street Extension, demolished 1954), the Government Assay Building (40 Wall Street), the Mutual Life Building, and the Manhattan Municipal Building (1 Centre St). He was also one of five consulting engineers in charge of the New York Barge Canal (1814 - 1915) and developed a plan to build a dam in the whirlpool Rapids of the Niagara Falls. For a time, he served as chief engineer for Arthur Mullin, the foundation contractors behind some of Manhattan's early skyscrapers. He worked as a consulting engineer for the city until a week before his death of stroke, at age 88. Although his contributions to American engineering are innumerable, Thomson is best remembered today for proposing a massive extension of Manhattan into New York Harbor - although it never happened, the proposal received national media attention and is remarkably persistent, having been reproposed as recently as 2022.