Thomas Moonlight was born in Scotland on September 30, 1833. Moonlight immigrated to the United States around 1851 and enlisted in the US Army when he was 20 years old. As an orderly sergeant in Company D, 4th US Artillery, Moonlight served in Florida, Texas and Kansas. After mustering out in 1858, Moonlight took up farming near Leavenworth in the Kansas Territory. When the Civil War started, Moonlight volunteered, raising a battery of light artillery and mustering in as a captain in July 1861. In April 1862, Captain Moonlight was appointed assistant adjutant general for the Department of Kansas. When the 11th Kansas Infantry was organized, Moonlight mustered in as its lieutenant colonel. During the Prairie Grove campaign, Moonlight served as chief of staff to Brig. Gen. James G. Blunt. In April 1864, Moonlight was promoted to colonel and placed in command of the 2d Brigade, District of South Kansas, District of the Frontier.

During Price’s 1864 invasion of Missouri Moonlight commanded the 2d Brigade in Maj. Gen. James G. Blunt’s Provisional Cavalry Division, Army of the Border. Moonlight was key in defending the bridge over the Little Blue River on Friday, October 21, 1864.

Following Price’s 1864 Raid, Moonlight was placed in command of Sub-District No. 3, District of South Kansas, Department of Kansas with his headquarters at Paola, Kansas. Less than a month later, Moonlight was in command of the District of Colorado relieving Col. John M. Chivington. Moonlight was ordered to conduct an investigation into Chivington’s actions during the Sand Creek Massacre. In April 1865, Moonlight was reassigned to command the Northern Sub-District of the Plains with his headquarters at Fort Laramie, Dakota Territory. Moonlight received a promotion to brevet brigadier general in February 1865 mustered out of the 11th Kansas Cavalry in July 1865 at Fort Kearney. After he mustered out, Moonlight returned to Leavenworth and entered politics, being elected as Kansas Secretary of State in 1868. Moonlight left eh Republican Party and was elected in 1872 to the Kansas State Senate as a Democrat. President Grover Cleveland appointed Moonlight territorial governor in Wyoming in 1887 and then in 1893, President Cleveland appointed Moonlight as minister to Bolivia.