After World War I, he (co[4]) founded[5][1][6][7] the Union des Blesses de la Face et de la tête (association of the wounded to the face and the head). Brunschwig was also a "discreet treasurer and financier" of the association.[4] He served as its president 1970-1972.[8]
In June, 1944, as colonel of the Free French Forces, he led the Free French Military Liaison Mission to the United States Forces. Brunschwig headed 200 French liaison officers who landed in Operation Overlord, joining the battle for the liberation of Europe.[2]
Roger Brunschwig joined his father, Achille who founded[1][12] Brunschwig & Fils Inc. Around 1925, he brought the company to the US,[13] soon, the company had opened showrooms in New York and other American cities.[14] In 1929, he married Zelina Brunschwig. She joined his textile firm in 1941 as a stylist.[15][16]
After World War II, Brunschwig and his interior designer wife, Zelina, expanded Brunschwig & Fils to include wallpapers and trimmings.[13]
Brunschwig died on December 7, 1972, in New York City.[2]