First, 1st Battalion, 1st Marines, 1st Cavalry, 1st Reconnaissance Battalion, 1st Operations Group, 1st Regiment, 1st Mounted Division, 1st Senate district, 1st Fighter Brigade, 3rd Battalion, 1st Marines, 1st Division, Royal 1st Devon Yeomanry, 1st Rifle Division, 1st Armoured Infantry Brigade (United Kingdom), 1st Brigade Combat Team, 1st Cavalry Division (United States), 1st Pennsylvania Regiment, 1st Word, 1st Hussars, 1st Squadron, 1st Cavalry Regiment, 1st Reconnaissance Squadron, 1st Theater Sustainment Command, 1st Marine Expeditionary Brigade (United States), 2nd Battalion, 1st Marines, 1st Brigade, 1st Armored Division (United States), 1st Brigade Combat Team, 1st Infantry Division (United States), 1st Marine Regiment (United States), 1st & Ten, 1st Michigan Infantry Regiment, 1st Brigade Combat Team, 1945–46 Danish 1st Division, 1951–52 Danish 1st Division, 1st Distribution Support Battalion, 1st Artillery Regiment, 1955–56 Danish 1st Division, 1949–50 Danish 1st Division, 1948–49 Danish 1st Division, 1946–47 Danish 1st Division, 1st Airborne, 1947–48 Danish 1st Division, 1st Engineer Regiment (Italy)

1st Bombardment Wing, 1952–53 Danish 1st Division, 1950–51 Danish 1st Division, 1st Constitution Bancorp, 1954–55 Danish 1st Division, 1st Marine Division, 1953–54 Danish 1st Division, 1st Air Defense Artillery Regiment, 1st Missouri Infantry, 1st Division (Thailand), 1st Armoured Brigade (United Kingdom), 1st Brigade (Australia), 1st Delaware Infantry Regiment, 1st (UK) Division, 1st Battle Squadron, 1st Belorussian Front, 1st Airborne Command Control Squadron, 1st ward, Chicago, 1st (African) Division, 1st Combat Engineer Battalion, 1st Armored, 1st Infantry Division (United States), 1st Colorado Infantry Regiment, 1st Horse (Skinner's Horse), 1st Division (Australia), 1st Medical Brigade, 1st Canadian Parliament, 1st Expeditionary Rescue Group, 1st Infantry Regiment (United States), 1st Royal New South Wales Lancers, Ōita 1st district, 1st Georgia Infantry Regiment, Francis Cook, 1st Viscount of Monserrate, 1956–57 Danish 1st Division, 1st Fighter Wing, 1st Light Car Patrol (Australia), 1st Armored Division (France), 1st Anti-Aircraft Brigade, 1st Test and Evaluation Squadron, 1st Infantry Division (France), 1st Source, 1st Fighter Squadron, 1st Cavalry Division (United States), 1st Brahmans, 1st (Peshawar) Division, 1st Cavalry Regiment (United States), 1st Pontieri Regiment, 1st Foreign Regiment (France), 1st Low Altitude Air Defense Battalion, 1st Maryland Cavalry Regiment

First, 1st Battalion, 1st Marines, 1st Cavalry, 1st Reconnaissance Battalion, 1st Operations Group, 1st Regiment, 1st Mounted Division, 1st Senate district, 1st Fighter Brigade, 3rd Battalion, 1st Marines, 1st Division, Royal 1st Devon Yeomanry, 1st Rifle Division, 1st Armoured Infantry Brigade (United Kingdom), 1st Brigade Combat Team, 1st Cavalry Division (United States), 1st Pennsylvania Regiment, 1st Word, 1st Hussars, 1st Squadron, 1st Cavalry Regiment, 1st Reconnaissance Squadron, 1st Theater Sustainment Command, 1st Marine Expeditionary Brigade (United States), 2nd Battalion, 1st Marines, 1st Brigade, 1st Armored Division (United States), 1st Brigade Combat Team, 1st Infantry Division (United States), 1st Marine Regiment (United States), 1st & Ten, 1st Michigan Infantry Regiment, 1st Brigade Combat Team, 1945–46 Danish 1st Division, 1951–52 Danish 1st Division, 1st Distribution Support Battalion, 1st Artillery Regiment, 1955–56 Danish 1st Division, 1949–50 Danish 1st Division, 1948–49 Danish 1st Division, 1946–47 Danish 1st Division, 1st Airborne, 1947–48 Danish 1st Division, 1st Engineer Regiment (Italy), 1st Bombardment Wing, 1952–53 Danish 1st Division, 1950–51 Danish 1st Division, 1st Constitution Bancorp, 1954–55 Danish 1st Division, 1st Marine Division, 1953–54 Danish 1st Division, 1st Air Defense Artillery Regiment, 1st Missouri Infantry, 1st Division (Thailand), 1st Armoured Brigade (United Kingdom), 1st Brigade (Australia), 1st Delaware Infantry Regiment, 1st (UK) Division, 1st Battle Squadron, 1st Belorussian Front, 1st Airborne Command Control Squadron, 1st ward, Chicago, 1st (African) Division, 1st Combat Engineer Battalion, 1st Armored, 1st Infantry Division (United States), 1st Colorado Infantry Regiment, 1st Horse (Skinner's Horse), 1st Division (Australia), 1st Medical Brigade, 1st Canadian Parliament, 1st Expeditionary Rescue Group, 1st Infantry Regiment (United States), 1st Royal New South Wales Lancers, Ōita 1st district, 1st Georgia Infantry Regiment, Francis Cook, 1st Viscount of Monserrate, 1956–57 Danish 1st Division, 1st Fighter Wing, 1st Light Car Patrol (Australia), 1st Armored Division (France), 1st Anti-Aircraft Brigade, 1st Test and Evaluation Squadron, 1st Infantry Division (France), 1st Source, 1st Fighter Squadron, 1st Cavalry Division (United States), 1st Brahmans, 1st (Peshawar) Division, 1st Cavalry Regiment (United States), 1st Pontieri Regiment, 1st Foreign Regiment (France), 1st Low Altitude Air Defense Battalion, 1st Maryland Cavalry Regiment, 1st Parachute Division (Germany), 1st Wisconsin Infantry Regiment, 1st Special Operations Squadron, 1st Civil Affairs Group, 1st Provisional Marine Brigade, 1st Earl of Suffolk, Joseph Maclay, 1st Baron Maclay, 1st Battalion, 5th Marines, 1st Air Cavalry Brigade, 1st Earl Temple, 1st Marine Logistics Group, 1st Airlanding Brigade (United Kingdom), 1st Canadian Division, 1958 Danish 1st Division, 1959 Danish 1st Division, 1960 Danish 1st Division, 2002–03 Danish 1st Division, 2003–04 Danish 1st Division, 1st millennium BC, Komandarm 1st rank, Captain 1st rank, 1st Ski Division (Wehrmacht), 1st Guards Brigade (Croatia), 1st Aviation Regiment (United States), 1st Health Battalion (Australia), 1997–98 Danish 1st Division, 1st Marine Aircraft Wing, 1st Maryland Cavalry Battalion, Potomac Home Brigade, 1st Armoured Division (Australia), 1996–97 Danish 1st Division, 1st Time, 1999–2000 Danish 1st Division, 2000–01 Danish 1st Division, 1st GAM: Amai Yuwaku, 2001–02 Danish 1st Division, 1st Minnesota Infantry Regiment, 1st Viscount Hampden, 1st Force Reconnaissance Company, 1st Strategic Aerospace Division, 1st Brigade (New Zealand), 1st Army Corps, 1st Armored Brigade (People's Republic of China), 1995–96 Danish 1st Division, 1st Airlift Squadron, 1st Photographic Group, 1st Missouri Cavalry Regiment (Union), 1st Infantry Regiment (Lithuania), 1st Commonwealth Division, 1st of tha Month, 1st Tactical Missile Squadron, 1st Air Fleet, 1st Regiment, Royal Australian Artillery, 1st Helicopter Squadron, Active Privy Councillor, 1st class, 1st Amphibious Mechanized Infantry Division, 1st Battalion, 227th Aviation Regiment (United States), 1st Australian Horse, 2004–05 Danish 1st Division, 2009–10 Danish 1st Division, 1st Battalion (Australia)