Union Staff Bureaux

General in Chief

Major-General Winfield Scott 25 June 1841-1 November 1861
Major-General George Brinton McClellan 1 November 1861-de facto 17 March 1862 officially 22 July 1862
(Major-General Ethan Allen Hitchcock Chairman of the War Board 17 March 1862-22 July 1862)
Major-General Henry Wager Halleck 11 July 1862-4 March 1864
Lieutenant-General Ulysses Simpson Grant 4 March 1864-31 December 1865

Adjutant-General’s Department

Colonel Samuel Cooper, Adjutant-General 15 July 1852-7 March 1861
Colonel Lorenzo Thomas, Adjutant-General 7 March 1861-1 July 1861
Colonel Catharinus Putnam Buckingham, Adjutant-General 1 July 1861-3 August 1861
Brigadier-General Lorenzo Thomas 3 August 1861-23 March 1863
Colonel Edward David Townsend, Acting Adjutant-General 23 March 1863-31 December 1865

Inspector-General’s Department

Colonel Sylvester Churchill, Inspector-General 25 June 1841-9 August 1861
Brigadier-General Randolph Barnes Marcy, Inspector-General 9 August 1861-31 December 1865

Quartermaster-General’s Department

Brigadier-General Joseph Eggleston Johnston, Quartermaster-General 28 June 1860-22 April 1861
Brigadier-General Montgomery Cunningham Meigs, Quartermaster-General 15 May 1861-31 December 1865

Commissary Department

Colonel George Gibson, Commissary-General of Subsistence 18 April 1818-21 September 1861
Brigadier-General Joseph Pannell Taylor, Commissary-General of Subsistence 21 September 1861-29 June 1864
Brigadier-General Amos Beebe Eaton, Commissary-General of Subsistence 29 June 1864-31 December 1865

Ordnance

Lieutenant-Colonel Henry Knox Craig, Chief of Ordnance 10 July 1851-23 April 1861
Brigadier-General James Wolfe Ripley, Chief of Ordnance 23 April 1861-15 September 1863
Brigadier-General George Douglas Ramsay, Chief of Ordnance 15 September 1863-12 September 1864
Brigadier-General Alexander Brydie Dyer, Chief of Ordnance 12 September 1864-31 December 1865

Engineers

Brigadier-General Joseph Gilbert Totten, Chief of Engineers 7 December 1838-22 April 1864
Brigadier-General Richard Delafield, Chief of Engineers 22 April 1864-5 June 1864
Brigadier-General John Gross Barnard, Chief of Engineers 5 June 1864-31 December 1865

Provost Marshal General’s Department

Brigadier-General James Barnet Fry, Provost Marshal General 21 April 1864-31 December 1865

Paymaster-General’s Department

Colonel Benjamin Franklin Larned, Paymaster-General 20 July 1854-12 July 1862
Colonel Timothy Patrick Andrews, Paymaster-General 12 July 1862-29 November 1864
Colonel Benjamin Wilson Brice, Paymaster-General 29 November 1864-31 December 1865

Surgeon-General’s (Medical) Department

Colonel Thomas Lawson, Surgeon-General November 30 1836-15 May 1861
Colonel Clement Alexander Finley, Surgeon-General 15 May 1861-14 April 1862
Surgeon Robert C Wood, Acting Surgeon-General 14 April 1862-25 April 1862
Brigadier-General William Alexander Hammond, Surgeon-General 25 April 1862-18 August 1864
Brigadier-General Joseph K Barnes, Surgeon-General 18 August 1864-31 December 1865

Topographical Engineers

Colonel John James Abert, Chief of Topographical Engineers 1838-September 1861-1863

Judge Advocate-General’s Department

Captain John Fitzgerald Lee, Judge Advocate-General March 2 1849-3 September 1862
Brigadier-General Joseph Holt, Judge Advocate-General 3 September 186231 December 1865