Isaac Roosevelt (December 19, 1726 – October 1794) was an American merchant and Federalist politician.

[1] He was the second generation of what would later come to be known as the Hyde Park, New York branch of the extended Roosevelt family.

Isaac's fortune from the refining of sugar, and his political accomplishments, became an essential root of the substantial wealth, prominence and influence that the Hyde Park Roosevelts came to amass.

During the 1700s, sugar was Europe's most valuable traded agricultural commodity, and it was cultivated almost entirely by slave labor in the Caribbean.

[4] Sugar cultivation also entailed an especially high death rate among slaves, due to difficult conditions and disease.

The trade was so lucrative that Wall Street’s most impressive buildings were Trinity Church at one end, facing the Hudson River, and the five-story sugar warehouses on the other, close to the East River and near the busy slave market.

"[5] Roosevelt built one of the first sugar refineries in the city, and originally had his store on Wall Street, later removing to St. George's Square.

Isaac Roosevelt is removed from his house in Wall Street to the house of his late brother, Jacobus Roosevelt, Jr., deceased, near the Sugar house, and opposite to Mr. William Waltons, being on the northwest side of Queen Street, where his customers may be supplied as usual with double, middling and single refined loaf sugars, clarified, muscovado and other molasses, & etc.

[7] After the war, as one of ten representatives from New York City (among John Jay, Alexander Hamilton,[10] and Robert R. Livingston), he took part in the New York State Convention at Poughkeepsie on June 18, 1788, that deliberated on the adoption of the United States Constitution.