After leaving college in the spring of 1861, Thorp assisted in raising a company in Granger; it was accepted for service as Company E,
85th New York Infantry Regiment in August, and in September Thorp enlisted for three years as a
private. In November, he was commissioned as a
captain and appointed to command the company. Thorp's speech on the right of the people to crush the rebellion roused the prisoners to such an extent that Confederate officers entered the camp and halted him. During his imprisonment, Thorp attempted several escapes, including one that nearly succeeded when he jumped from a train between Savannah and Charleston; he was recaptured only because his pursuers used bloodhounds to track him. Thorp was paroled in March 1865. He then returned to New York to recuperate, and he was there when the war ended in April 1865. He took part in the
Grand Review of the Armies in May and received his discharge in June. Thorp was promoted to
colonel in March 1865, and in July 1889 this promotion was made retroactive to December 24, 1864. Wounded five times in total, in October 1865, he received the
brevet of
brigadier general of
United States Volunteers in recognition of the superior service he rendered during the war. ==Continued career==