On 12 November 1890, while in Philadelphia, Philippe joined the Pennsylvania Commandery of the Military Order of the Loyal Legion of the United States (MOLLUS) - a military society composed of officers who had served the Union in the American Civil War and their descendants, as a companion of the 2nd class - a membership category for the eldest sons of companions of the 1st class who were veteran officers. He was assigned MOLLUS insignia number 8262. Upon his father's death on 8 September 1894, he became a hereditary companion of the 1st class.