He was elected vice-president and principal of Galesburg University and served there for two years, then became minister of the Methodist Episcopal Church in Oshkosh, Wisconsin.

In 1862, however, he resigned his ministry and enlisted for service in the Union Army, becoming chaplain of the 32nd Wisconsin Infantry Regiment under Colonel James Henry Howe.

[6]: 800  He served for a year with the regiment which mostly performed guard duty during that time to protect supplies and logistics along the Mississippi River in the Western Theater of the American Civil War.

[4]: 231 [6]: 866  The 49th Wisconsin mustered into service on March 8, 1865, and proceeded to St. Louis and then to Rolla, Missouri, where they engaged in guard duty through the end of the war.

[4]: 231 On January 13, 1866, U.S. President Andrew Johnson nominated Colonel Fallows for a brevet to brigadier general of volunteers in recognition for his service.

In 1870, when the State Superintendent of Public Instruction Alexander J. Craig died in office, Fairchild appointed Fallows to fill that position.

[9][10] After his service in the war, Colonel Fallows became a companion of the Illinois Commandery of the Military Order of the Loyal Legion of the United States and was the chaplain of the Grand Army of the Republic.

[4]: 231 Fallows died after a bad case of influenza at his home in Chicago on September 5, 1922, with his daughter Alice at his bedside.