First 1st Battalion, 1st Marines 1st Cavalry 1st Reconnaissance Battalion 1st Operations Group 1st Mounted Division 1st Regiment 1st Division 1st Senate district 1st Fighter Brigade 3rd Battalion, 1st Marines Royal 1st Devon Yeomanry 1st Rifle Division 1st Armoured Infantry Brigade (United Kingdom) 1st Brigade Combat Team, 1st Cavalry Division (United States) 1st Word 1st Hussars 1st Pennsylvania Regiment 1st Theater Sustainment Command 1st Marine Regiment (United States) 1st Reconnaissance Squadron 1st Squadron, 1st Cavalry Regiment 1st Battalion, 4th Marines 1st Armored Division (United States) 1st Brigade Combat Team, 1st Infantry Division (United States) 2nd Battalion, …

1st Marines 1st Brigade 1st & Ten 1st Michigan Infantry Regiment 1st Brigade Combat Team 1st Airborne 1945–46 Danish 1st Division 1951–52 Danish 1st Division 1st Artillery Regiment 1949–50 Danish 1st Division 1947–48 Danish 1st Division 1948–49 Danish 1st Division 1946–47 Danish 1st Division 1st Bombardment Wing 1st Air Defense Artillery Regiment 1955–56 Danish 1st Division 1950–51 Danish 1st Division 1st Marine Division Ōita 1st district 1954–55 Danish 1st Division 1952–53 Danish

1st Division 1st Constitution Bancorp 1st Division (Thailand) 1953–54 Danish 1st Division 1st Brigade (Australia) 1st Minnesota Infantry Regiment 1st Missouri Infantry 1st Armored 1st Battle Squadron 1st Airborne Command Control Squadron 1st (African) Division 1st Armoured Brigade (United Kingdom) 1st Delaware Infantry Regiment 1st Combat Engineer Battalion 1st Light Antiaircraft Missile Battalion 1st Belorussian Front 1st Horse (Skinner's Horse) 1st Colorado Infantry Regiment 1st Division (Australia) 1st Infantry Division (United States) 1st Expeditionary Rescue Group 1st Canadian Parliament 1st Fighter Squadron 1st Georgia Infantry Regiment 1st Infantry Regiment