Orders of Battle

40th Division Order of Battle, 1917  

Former state unit designations are noted in italics
Headquarters Company (Troop D, 1st Squadron, California Cavalry)
79th Brigade
157th Infantry Regiment (1st Colorado Infantry, 1 Colorado Cavalry)
158th Infantry Regiment (1st Arizona Infantry)
144th Machine Gun Battalion (elements of 1st New Mexico Infantry)
80th Brigade
159th Infantry Regiment (5th California Infantry, and elements of 2d California Infantry)
160th Infantry Regiment (7th California Infantry, and elements of 2d California Infantry)
145th Machine Gun Battalion (1st Squadron, California Cavalry)
65th Field Artillery Brigade
143d Field Artillery Regiment (1st California Field Artillery)
144th Field Artillery Regiment (2d California Field Artillery)
145th Field Artillery Regiment (1st Utah Field Artillery)
115th Trench Mortar Battery (Machine Gun Company, 2d Colorado Infantry)
115th Engineer Regiment (1st Colorado Engineers)
115th Field Signal Battalion (1st California and 1st Colorado Wire Companies)
115th Military Police Battalion (elements of 1st New Mexico Infantry)
115th Ammunition Train (elements of 2d Colorado Infantry)
115th Supply Train (elements of 2d Colorado Infantry)
115th Sanitary Train (later 115th Medical Regiment) (1st, 2d, 3d and 4th California Ambulance Companies, 1st and Second California, 1st Colorado, and 1st Utah Hospital Companies)

40th Infantry Division Order of Battle, January 1940  

All units are from the California National Guard, unless otherwise noted.
Headquarters, 40th Division Headquarters
Headquarters, Special Troops
40th Military Police Company (Nevada)
40th Signal Company
115th Ordnance Company (Utah)
115th Engineer Regiment (Utah and Nevada)
115th Medical Regiment (3d Battalion from Utah)
115th Quartermaster Regiment
40th Division Aviation
115th Observation Squadron
115th Photo Section
40th Tank Company
77th Infantry Brigade
159th Infantry Regiment
184th Infantry Regiment
80th Infantry Brigade
160th Infantry Regiment
185th Infantry Regiment
60th Field Artillery Brigade (Utah)
143d Field Artillery Regiment (75mm Howitzer)
145th Field Artillery Regiment (75mm Howitzer) (Utah)
222d Field Artillery Regiment (155mm Howitzer) (Utah)

40th Infantry Division Order of Battle, September 1945  

Division Headquarters
115th Engineer Combat Battalion
115th Medical Battalion
Special Troops
40th Signal Company
40th Military Police Platoon
740th Ordnance Light Maintenance Company
40th Quartermaster Company
40th Counter-Intelligence Corps Detachment
180th Language Detachment
40th Reconnaissance Troop
503d Parachute Infantry Regiment
160th Infantry Regiment
185th Infantry Regiment
Division Artillery
143rd Field Artillery Battalion (105mm Howitzer)
164th Field Artillery Battalion (105mm Howitzer)
213th Field Artillery Battalion (105mm Howitzer)
222th Field Artillery Battalion (155mm Howitzer)
Attached Units:
749th Field Artillery Battalion (8 Inch Howitzer)
20th Portable Surgical Hospital
21st Portable Surgical Hospital
175th Malaria Control Unit
216th Malaria Survey Unit

40th Infantry Division Order of Battle, 30 January 1953 

Division Headquarters
578th Engineer Combat Battalion
115th Medical Battalion
40th Signal Company
40th Military Police Company
740th Ordnance Battalion
40th Quartermaster Company
40th Infantry Division Band
40th Reconnaissance Company
40th Replacement Company
140th Tank Battalion
160th Infantry Regiment
223d Infantry Regiment
224th Infantry Regiment
Division Artillery
143rd Field Artillery Battalion (105mm Howitzer)
625th Field Artillery Battalion (105mm Howitzer)
980th Field Artillery Battalion (105mm Howitzer)
981st Field Artillery Battalion (155mm Howitzer)
140th Anti-Aircraft Artillery Automatic Weapons Battalion
Attached Units:
5th Regimental Combat Team
5th Infantry Regiment
72d Engineer Combat Company
555th Field Artillery Battalion
245th Tank Battalion
21st Chemical Decontamination Company
92d Chemical Service Company
388th Chemical Smoke Generator Company
2d Platoon, 86th Field Artillery Battery (Searchlight)
Mobile Army Surgical Hospital, 8076th Army Unit (Logistical Support)
40th Counter Intelligence Corps Detachment
507th Military Intelligence Service Platoon
Team 2, 1st Loudspeaker and Leaflet Company

40th Armored Division Order of Battle, 1956  

Division Headquarters
40th Military Police Company
40th Armored Signal Company
140th Replacement Company
132d Armored Engineer Battalion
40th Armored Division Train
40th Armored Quartermaster Battalion
40th Armored Ordnance Battalion
40th Armored Medical Battalion
40th Armored Division Band
Combat Command A
111th Reconnaissance Battalion
160th Armored Infantry Battalion
161st Armored Infantry Battalion
Combat Command B
133d Tank Battalion
134th Tank Battalion
224th Armored Infantry Battalion
Combat Command C
139th Tank Battalion
140th Tank Battalion
223th Armored Infantry Battalion
Division Artillery
215th Anti-Aircraft Artillery Battalion
143d Armored Field Artillery Battalion
214th Armored Field Artillery Battalion
215th Armored Field Artillery Battalion
225th Armored Field Artillery Battalion

40th Armored Division Order of Battle, 1968  

Division Headquarters
132d Engineer Battalion
240th Signal Battalion
140th Aviation Battalion
40th Armored Division Band
1st Brigade
1st Battalion, 160th Infantry
2d Battalion, 160th Infantry
3d Battalion, 160th Infantry
1st Battalion, 185th Armor
3d Battalion, 185th Armor
2d Brigade
4th Battalion, 160th Infantry
2d Battalion, 185th Armor
1st Reconnaissance Squadron, 18th Armored Cavalry
1st Squadron, 111th Cavalry
3d Brigade
4th Battalion, 185th Armor
5th Battalion, 185th Armor
6th Battalion, 185th Armor
Division Artillery
1st Battalion, 144th Field Artillery
2d Battalion, 144th Field Artillery
3d Battalion, 144th Field Artillery
4th Battalion, 144th Field Artillery
5th Battalion, 144th Field Artillery
Division Support Command
40th Medical Battalion
40th Maintenance Battalion
123d Maintenance Company
40th Supply and Transportation Battalion
540th Administration Company
40th Military Police Company

40th Infantry Division (Mech) Order of Battle, 1994 

Division Headquarters
40th Infantry Detachment
160th Infantry Detachment
40th Military Police Company
140th Chemical Company
40th Infantry Division Band
240th Signal Battalion
140th Military Intelligence Battalion (US Army Reserve)
1st Brigade
2d Battalion, 160th Infantry Regiment
3d Battalion, 160th Infantry Regiment
1st Battalion, 185th Armor Regiment
1st Battalion, 221st Armor Regiment (Nevada)
2d Brigade
4th Battalion, 160th Infantry Regiment
2d Battalion, 185th Armor Regiment
3d Battalion, 185th Armor Regiment
3d Brigade
2d Battalion, 159th Infantry Regiment
1st Battalion, 184th Infantry Regiment
1st Battalion, 149th Armor Regiment
Aviation Brigade
1st Squadron, 18th Cavalry Regiment
1st Battalion, 140th Aviation Regiment
Company D (Command), 140th Aviation Regiment
Company E (Assault), 140th Aviation Regiment
Company F (Aviation Intermediate Maintenance), 140th Aviation Regiment
Engineer Brigade
132d Engineer Battalion
579th Engineer Battalion
Division Artillery
1st Battalion, 143d Field Artillery Regiment
2d Battalion, 144th Field Artillery Regiment
3d Battalion, 144th Field Artillery Regiment
Battery D (Multiple Launch Rocket System), 144th Field Artillery Regiment
Battery F (Target Acquisition), 144th Field Artillery Regiment
Division Support Command
540th Main Support Battalion
40th Support Battalion
240th Support Battalion
340th Support Battalion