[1] His family included his father's brother, James Truesdell Kilbreth, an attorney who served as Collector of the Port of New York.

[7] In 1911, he was assigned to temporary duty as inspector general of National Guard units in the 2nd Inspection District, which included New York City.

[9] In addition, he was charged with neglect of duty for allegedly failing to visit units at remote locations beyond the New York City area.

[9] Kilbreth was prosecuted by John F. Madden and found guilty of disobeying orders for failing to respond to the Adjutant General of the United States Army's inquiries about the debts, and reduced several places on the captain's seniority list, but was not otherwise punished.

[11] When the United States entered World War I in April 1917, Kilbreth was stationed at Schofield Barracks, Hawaii with the 9th Artillery.

From August 1917 to May 1918, Kilbreth was director of the Department of Firing at the United States Army Field Artillery School, and he was promoted to temporary colonel in February 1918.

He remained in command through the end of the war in November 1918, and in December was assigned to staff duty at the American Expeditionary Forces headquarters.

He was primarily responsible for the excellent grounding received by thousands of officers in the principles of artillery firing, including those applicable to open warfare.