[5] After traveling from Constantinople to Paris, Williamson returned to the U.S. with French statesman Georges Clemenceau, who served as Prime Minister of France between 1917 and 1920.
[5] Williamson later served as a member of the editorial staff of the Sunday Times, and he penned the "Headline Footnotes" column.
He later transferred to Company M with the 9th Infantry and received a detail to the General Headquarters of the American Expeditionary Forces in Paris, France.
During his service in World War I, Williamson participated in the Aisne Defensive, the Battle of Saint-Mihiel, and the Meuse-Argonne Offensive.
[6] Williamson married Cora Mancia Chase, a soprano in the Metropolitan Opera in New York City, on May 5, 1923.