Despite being over 60 years old and having been out of the Army for 25 years, the crisis of the Union compelled Greene to seek to rejoin the service. He was essentially apolitical and was not an abolitionist, but he was a firm believer in restoring the Union. He was appointed colonel of the 60th New York Volunteer Infantry on January 18, 1862. The regiment of upstate New Yorkers had been dissatisfied with their colonel and the company commanders had petitioned for his removal. Governor Edwin D. Morgan, although initially reluctant to appoint Greene because of his age, saw his 13 years of regular army experience as a solution to his political/military problem. During this period, Governor John A. Andrew of Massachusetts was also prepared to offer Greene a regiment, but Greene chose to serve New York. The officers of the 60th were dismayed when the elderly, gray-haired man reported for duty. They had requested that their lieutenant colonel be promoted, which would have raised many of them in rank themselves.