A prominent member of the Ordnance Corps, he attained the rank of brigadier general, and was notable for planning and overseeing construction of Aberdeen Proving Ground, Maryland.

[4] After his assignment to Ordnance, Ruggles became an acknowledged expert in the design, production, and quality control inspection of artillery, small arms, and ammunition.

[4] During the Spanish–American War, Ruggles was offered promotion to temporary major in the United States Volunteers, which he declined in order to remain on duty at Frankford Arsenal.

[4] He served as professor of Ordnance and Gunnery at the United States Military Academy from August 1908 to June 1911, and was promoted to lieutenant colonel on April 13, 1911.

[8] From June 1911 to July 1913, Ruggles was assigned as Ordnance officer for the Army's Western Department and commander of Benicia Arsenal, California.

[4] From October to December 1918, Ruggles served on temporary inspection and observation duty with the American Expeditionary Forces in England and France.

[4] At the end of the war, he received the Army Distinguished Service Medal in recognition of his efforts to create Aberdeen Proving Ground.

The conception and construction of the Aberdeen Proving Ground and its operation during the early and most difficult period of its history are a monument to his sagacity and unremitting labor.After the war, Ruggles was assigned as Chief of the Ordnance Department's Technical Staff.

[4] He was a student at the United States Army War College from August 1921 to June 1922 and after graduating he returned to his post as Chief of the Technical Staff at the Ordnance Department.