[1] Deputy of nobility for the bailliage d'Amont in the Estates General of 1789 that became the National Constituent Assembly, Jean-Xavier Bureau de Pusy was three times named president of the National Constituent Assembly: He contributed actively to the division of France into 83 departments,[2] in 1790, and with the metric system.

[4] After the session of the National Constituent Assembly, he resumed as a captain in the engineering corps, and continued to defend the constitutional principles.

He was offered vast, land grants on the banks of the Delaware River, but he had not given up on returning to France, and when the consulate government had, after the coup of 18 Brumaire, struck off the list of émigrés members of the National Constituent Assembly who had recognized the sovereignty of the people, he hastened to return.

He was appointed prefect of Gênes (Genoa) on 15 Messidor year XIII (4 July 1805); he had to suppress a riot of Parma, and was able to without shedding a drop of blood.

His mother-in-law, Françoise Robin, married Pierre Samuel du Pont de Nemours.