The 46th Infantry was constituted in May 1917 as a part of the General Mobilization for World War 1. The 46th was assigned to the 9th Division just at the end of the war. The unit was inactivated November, 1921.
The 46th was reconstituted at Fort Knox as the 46th Armored Infantry, 5th Armored Division, in 1943. The regiment consisted of three battalions: the 46th, 15th, and 47th Armored Infantry Battalions.
The 46th Infantry participated in the Normandy Invasion, the Liberation of France, and reached the vaunted Seigfried Line in September, 1944. The 5th Armored Division liberated the Grand Duchy of Luxembourg and also had the distinction of being the first American unit to reach German soil.
All three battalions of the 46th fought in the three-month bloody campaign of the Hurtgen Forest. These were the worst, most difficult, and trying conditions of the European Theater. Casualties were extremely high and in December 1944, the 46th Armored Infantry Battalion lost half its effective strength in a single day, taking a stubbornly defended hill. Three men, including the battalion commander, won the Distinguished Service Cross that day. The sacrifices made in the Hurtgen Forest are symbolized by two pine trees, colored red, found in the Unit Crest.
Upon completion of the war in Europe, the 46th Infantry returned to the States and was deactivated in October, 1945. The regiment was activated and deactivated several times in the intervening years.
In May, 1967, the 46th Infantry deployed for Vietnam. Two battalions of the 46th (1st and 5th) served honorably rotating between the 23rd Infantry Division (Americal), 198th Infantry Brigade and the 196th Infantry Brigade. The battalions have credit for twelve campaigns, stretching from October, 1967 to June, 1972. During the battalion's service in Vietnam MAJ Kern Dunagan of Co A, 1st Battalion, 46th Infantry Regiment was awarded the Medal of Honor by President Richard M Nixon on 15 June 1971 for his actions on 13 May 1969.
The heritage of the 46th continues to grow. From 1987 to 2010, the Basic Training Battalions of the 46th Infantry trained and graduated Soldiers at Fort Knox of the same caliber as those who fought before them. Beginning in 2011, the 46th Infantry continues to produce the best soldiers in the world at Fort Benning. By the actions of these soldiers and many like them, the spirit and legacy of the regiment lives on. Thus, the unit continues to change as it has since origination in the days of World War I.