History of the Office of The Inspector General of the United States Army (IG January 10, 1863April 1, 1864; January 2, 1881March 8, 1885) was assigned as the "de facto" head of the Office of the Inspector General, which, until then had not existed. 2 major generals, 7 brigadier generals, 18 colonels, 118 lieutenant colonels, and 149 majors of the regular army served inspector duty during the Civil War. On January 22, 1866, a War Department order established the duties of the inspector general as: In July 1866, the number of inspectors general with the rank of colonel was fixed at four; assistant inspectors general with the rank of lieutenant colonel at three;
Comparative army officer ranks of the Americas Comparative army officer ranks of the Americas Rank comparison chart of all armies and land forces of North and South American states. Warrant Officers (WO) and Chief Warrant Officers (CWO) in the US Military rank below officers but above officer candidates and enlisted servicemen. The first warrant officer rank, WO1 does not have a "commission" associated with it, instead having a "Warrant" from the Secretary of the Army. Warrant officers are allowed the same courtesies as a commissioned officer, but may have some restrictions on their duties that are reserved for commissioned officers. Warrant officers usually receive a commission once