He served as President of the Senate of France (1852–1869) and was a member of the Académie des sciences morales et politiques.

In 1835, he was appointed advisor of the Court of Cassation, while in 1840, he became a member of the Academy of Moral and Political Sciences (Legislation section).

Then he became rapporteur of the sénatus-consulte under Napoleon III (Second French Empire); Troplong legitimized Napoleon III's coup d'état with this argument: The Republic is practically within the Empire because of the contractual nature of the institution and of the communication, and because of the express delegation of power by the people; but the Empire prevails over the Republic because that is also a monarchy, i.e. the government of everybody confined by the moderating action of one person having heredity as a condition and stability as a resultHe replaced the prince Jerome Bonaparte when he resigned from his position of President of the Senate of France on December 30, 1852.

He knew and discussed the work of Friedrich Carl von Savigny, the founder of the German "Ecole historique du droit", and defended neighboring but distinct positions, which seems to prove, despite what has been argued by certain authors (Julien Bonnecase, The School of Exegesis in Civil Law, 1924) his influence on the legal doctrine.

After death, he wanted to be buried together with his only daughter Joséphine Marie-Louise, who had died in Plombières-les-Bains in October 1839 when she was in that city with her parents for a few days of relaxation; the little girl was just eight years old.