The son of a farmer, he served time as a private in the dragoons then (at the start of the French Revolution) moved to farming and raising his large family.
He was very severe with incompetent generals, notably dismissing Jean Nestor de Chancel and Jean-Baptiste Davaine who were both executed.
Sent back to the Nord, then to Moselle, according to his colleague Nicolas Hentz, Duquesnoy forgot his dignity as a representative and behaved with an insupportable despotism.
Recalled to Paris on 10 August 1794, he succeeded in excluding Jean-Lambert Tallien from the club des Jacobins and having Armand-Joseph Guffroy beaten before Carnot.
Guffroy complained to the Committee of General Security and, accused of being one of the leaders of the insurrection of 1 prairial an III (20 May 1795), Duquesnoy was condemned to death despite his friends' depositions.