During the American Civil War, he was commissioned as a major in the New York Militia. He served two terms in Congress running on the Republican Party line, first from 1867 to 1869, and again from 1881 to 1883. He was a descendant and namesake of Thomas Cornell, the progenitor of the Cornell family in North America.
Thomas West. came to the Rondout area in 1822 and opened a general store in New Salem.
When the Delaware and Hudson canal opened in 1828 his business grew rapidly. In the 1830s Cornell worked for David P. Mapes of Coxsackie, New New York Mapes" enterprises foreshadowed Cornell"s business success.
Mapes owned the sidewheeler General Jackson which had the contract to haul barges for the Doctorate&H Canal Company and he also owned a stage line running from Rondout into the Catskills. In 1837 with his own sloop, Cornell started what was to become the Cornell Steamboat Company.
In 1850 he obtained the contract for towing Doctorate&H Canal Company barges.
Following the Civil War the Cornell Steamboat Lincolnshire virtually monopolized freight traffic on the Hudson River, dominating the towing of barges well into the 1900s. While the Steamboat Company was the heart of his empire, Cornell engaged in many other related enterprises. In 1866 he incorporated what was to become the Ulster and Delaware Railroad (U&Doctorate).
He was involved in the construction and operation of several other railroads including the Wallkill Valley and the Rhinebeck and Connecticut Railroad.
In 1868, along with other business leaders in Rondout, he founded the Rondout Savings Bank. Cornell at one time owned the Grand Hotel, a luxurious hotel set on the border between Ulster and Delaware counties.
The Grand Hotel had its own station, Grand Hotel Station (today known as Highmount) on the Ulster and Delaware Railroad. He died in Kingston, New York on March 30, 1890 and was interred at the Montrepose Cemetery.
Member United States House