[1][2] The mayors of the Parisian suburbs of Boulogne-sur-Seine, Issy, Saint-Denis, Saint-Ouen, Le Pré-Saint-Gervais and Pantin belonged to the party.
[2] Prominent members of the party included Georges Pioch, Victor Méric and Ernest Lafont.
[3] U.S.-C. suffered a major setback Frossard and other prominent members (such as Henri Sellier) returned to the French Section of the Workers International (SFIO) in 1924.
[7][8] The party published L'Egalité (started by Frossard's group in January 1923) until April 1924.
The publishing of L'Egalité was suspended after the crisis in the party that followed the return of Frossard and other prominent members to SFIO.