As a military veteran of the Union forces of the Civil War, Zephaniah Phillips filled out many pension application papers. This War Department memo from the Adjutant General's Office, written in 1882, was submitted to the Commissioner of Pensions and it lists the highlights of his military service and is signed by the Assistant Adjutant General. It reads:

Zephaniah Phillips, a musician of Company B, 1[st] Regiment, Ills. Cavalry Volunteers, was enrolled on the 25th day of June, 1861, at Equality, Ills., and is reported: Present, on roll from date of enrollment to Augt. 31, 1861. He was mustered out with Co., at Springfield, Ills Nov. 23, 1861, by order from the War Dept., having been taken prisoner at the battle of Lexington Mo., Sept. 20, 1861, and released on parole.
Zephaniah Phillips, [private?] Co. F, 56 Ills. Vols. enrolled Nov. 15, 1861 at McLeansboro, Ill., and mustered in Feb. 27, 1862. Roll dated Feb. 28, 1862 reports him present, Roll for March and April, '62, at home on sick furlough. Roll for May & June, '62, at home sick. Roll for July & Aug., '62, furloughed by Col. S. Noble at Paducah, Ky., April 29, 1862. "Discharged the service August 5, 1882 [sic] to date Augt. 20, 1862, by order of the Secretary of War to complete his military history."