Charles DeKay Cooper (1769 – January 30, 1831) was an American physician, lawyer[clarification needed] and Democratic-Republican politician.
In 1794, he was appointed Health Officer of the Port of Albany In February 1804, Cooper attended a dinner party during which Alexander Hamilton spoke forcefully and eloquently against the Federalists' plan to nominate Aaron Burr as their candidate for Governor of New York.
The letter was published in The Albany Register, but was tame compared to other attacks on Burr in the press.
Still, Cooper's letter proved the last straw in the ongoing rivalry between Burr and Hamilton.
In April 1817, while his father-in-law was Acting Governor, Cooper was appointed Secretary of State of New York.