He was appointed maréchal de camp in 1791; He was appointed Governor of the west province of Saint-Domingue (now Haiti) the following year, and twice governor-general. He was eventually a brigadier general.
In lighter moments he wrote a successful comedy in verse, in three acts, L' oncle et les tantes ("Uncle and aunts"), which was reprinted in 1786. Previously he had supplied the libretti for at least two one-act operas for which the music was composed by François-Joseph Gossec. One, Le périgourdin ("The man from Périgord") was an intermède, a between-acts intermezzo that was presented at the private theatre of the prince de Conti at the Château de Chantilly, 7 June 1761. His one-act pastoral comedy Les Pêcheurs, ("The Fishermen") was presented to a Parisian public at the Comédie-italienne, 23 April 1766 and repeated 7 July. His translation of an English novel Histoire de Lucy Wellers, by "Miss Smythies of Colchester" was printed at The Hague in 1766.
The marquis de La Salle was a member of two Masonic lodges in Paris, that of St-Jean d’Ecosse du Contrat Social, then that of Les Neuf Sœurs (1778-1785), where he succeeded Benjamin Franklin as vénérable in 1781.
A Mémoire justificatif pour le marquis de la Salle was printed in 1789.
The Château de Piédefer, Viry-Chatillon, Essonne, near the Seine south of Paris, traditionally attributed to Charles Perrault, is known for its late-seventeenth-century vaulted nymphaeum or grotto encrusted with rock and shellwork in compartments, and an orangery, both listed as Monuments historiques since 1983. The seventeenth-century architecture of the château was modified in the eighteenth century; a parterre survives, with a water jet in a fountain, in the nineteenth-century wooded landscape park.