[b]Late 20th Century Organization [/b] In 1959, the US Army discarded their regimental system of organizing their army resulting from lessons learned during WWII, Korean War and training experiences of the 1950's. The Combined Arms system went deeper into the organization in this year. Instead of having pure branched regiments of Infantry, Armor and Field Artillery, they were broken up into Battalions. Every Battalion would consist of the following: Battalion Headquarters Company (battery for FA and troop for cavalry) 4x Line Companies 1x Weapons Company To further implement the Combined Arms integration, Divisions used Brigades for Subordinate Command instead of Regiments. An Armor Division consisted of five Armor Battalions, five Mechanized Infantry Battalions, three direct support Field Artillery battalions, a general support artillery battalion, a Division Artillery Brigade (DIVARTY), Division Support Command (DISCOM) and eventually the Division Aviation Brigade. A Mechanized Infantry Division consisted of four Armor Battalions, six Mech Infantry Battalions, DIVARTY, DISCOM and AVN BDE. This organization existed until 2005. I retired before the final change occurred. During the Vietnam War, the rifle squad was composed of 11 soldiers; the squad leader and two fire teams. The fire team was composed of a team leader, Automatic Rifleman (He fired his rifle on full auto), Grenadier (M79 Grenade Launcher) and two Rifleman. The Machine guns in the Company Weapons Platoons were then parceled out to Infantry Platoon level. A Rifle Platoon during Vietnam consisted of three 11-man squads, the Platoon headquarters (3 men) and 2 Machine gun teams of 6 men. This gave the Vietnam Rifle Platoon a strength of 42 soldiers. The 1970's witnessed the invention of the M203 Grenade Launcher which is attached to the bottom of the rifle. This simple invention reduced the size of a rifle squad from 11 men to 9 men. The M203 removed the Grenadier (M79) and one Rifleman. The introduction of the M47 Dragon Wire Guided Anti-Tank (AT) Missile replaced the older AT guns. By this time the Army had been using 90mm Recoilless Rifles for AT purpose. The M47 was introduced to the Platoon and the Recoilless Rifles went away. A 1980's Rifle Platoon consisted of Platoon HQs (Platoon Leader, Platoon Sergeant & Radio/Telephone Operator - RTO) three 9-man Rifle Squads one Weapons Squad The Weapons Squad consisted of the Squad leader, 2 machine gun teams (6 soldiers) and 2 Dragon gunners (M47). The 1980s Rifle Platoon boasted a strength of 39 soldiers. Light Infantry units changed again in the 1990's removing all the M47 Dragons to an AT Section at Company level and reduced the MG teams to 2 men instead of 3. The 81mm Mortar Platoon left company level and a Light Weight Company Mortar (LWCM) section consisting of 6 men and 2x 60mm mortars took their place. The 4.2" Battalion mortar was replaced with the 81mm Mortar. To understand the current organization, one must compare it to the previous one. Prior to the 2005 change, there were three maneuver Brigades, Divarty, Discom and the Aviation Brigade. Since a Mech Infantry Division had four Armor and six mech Infantry battalions, those were organized however the Division Commander wanted to organize them. A Peace time organization could have looked like this: [u][b]4th Infantry Division (Mechanized)[/b][/u] [b]1st Brigade[/b] 1st Bn, 8th IN (M) 2nd Bn, 8th IN (M) 1st Bn, 69th AR 2nd Bn, 69th AR [b]2nd Brigade[/b] 3rd Bn, 8th IN (M) 1st Bn, 12th IN (M) 3rd Bn, 69th AR [b]3rd Brigade[/b] 3rd Bn, 12th IN (M) 1st Bn, 22nd IN (M) 1st Bn, 70th AR [b]DISCOM[/b] 4th Engineer Battalion 4th Medical Battalion 1st Battalion 161st Air Defense Artillery (ADA) 124th Signal Battalion 1st Battalion 20th Transportation 704th Maintenance Battalion 412th Maintenance Battalion 4th AG Company 4th Finance Company 4th MP Company 704th MI Battalion 4th ID Band [b]DIVARTY[/b] 2nd Bn, 9th FA (DS) M109 155mm SP 6th Bn, 29th FA (DS) M109 155mm SP 4th Bn, 77th FA (DS) M109 155mm SP 5th Bn, 16th FA (GS) 8" SP [b]AVN BDE[/b] 1st Squadron 10th Cavalry (Armored) 4th Aviation Battalion When a Maneuver Brigade goes to the field or wartime, slice elements from DISCOM and DIVARTY are generally attached to the Brigade. So in this case, the 1st Brigade goes to the field with its 4 maneuver Battalions plus a Fire Support Team from the 2nd Bn, 9th Field Artillery; it's Direct Support Artillery Battalion. The FA Bn Commander becomes the Fire Support Coordinator for the Brigade. One of the companies from the 704th Maint Battalion will go to the field with the Administrative and Logistics Operations Center (ALOC) of the 1st Brigade. A slice element from 4th Engineers, 4th Medical Battalion, 1st Battalion 161st Air Defense Artillery (ADA), 124th Signal Battalion, 1st Battalion 20th Transportation and the 704th MI Battalion all go with the 1st Brigade to the field. The DISCOM which is a brigade level echelon is purely a peacetime administrative organization. During Field Training Exercises and wartime, they dissolve.