The 1st Ranger Battalion was authorised, On 19th June 1942, they were recruited, and began training in Carrickfergus, Northern Ireland. From 500 enlistees who first formed the Rangers at Carrickfergus, only 87 remained by the end of the war. There was 80 percent of the first Rangers that came from the 34th Infantry Division.

A select fifty or so of the first U.S. Rangers were scattered through the Canadian and British Commandos for the Dieppe Raid in August 1942.

Collectively with the ensuing 4th and 3rd Ranger Battalions, they fought in North Africa and Italy commanded by Colonel William Orlando Darby until the Battle of Cisterna ( 29 January 1944 ) when most of the Rangers of the 1st and 3rd Battalions were apprehended. Of the 767 men in the battalions, 761 were killed or captured. The surviving Rangers were incorporated into the Canadian-American First Special Service Force under Brigadier General Robert T. Frederick. They were then effective in operations in and around the Anzio beachhead that followed Operation Shingle.

Before the 5th Ranger Battalion landing on Dog White sector on Omaha Beach, during the Invasion of Normandy, the 2nd Ranger Battalion scaled the 90-foot (27 m) cliffs of Pointe du Hoc, a few miles to the west, to defeat a five-gun battery of captured French Canon de 155 mm GPF guns. The gun positions were clear on the day and the weapons had been removed sometime before to allow the formation of casements in their position. (one of the gun stations was bombed by the RAF in May – prior to D-day – leaving 5 missing guns). Under persistent fire during their climb, they confronted only a small company of Germans on the cliffs and consequently found a group of field artillery weapons in trees some 1000 yards to the rear. The guns were disabled and destroyed, and the Rangers then cut and secured the main road for two days before being relieved. All whilst being strengthened by members of the 5th Ranger Battalion who came at 6pm on the 6th of June from Omaha Beach. More 5th Ranger units arrived by sea on the 7th of June when some of their injured along with German prisoners were taken away to the waiting ships.

At this moment there is no memorial exists at Pointe du Hoc to commemorate the actions of the 5th Rangers at Pointe du Hoc – only one to the members of the 2nd Battalion. The United States Battlefield Monuments Commission have announced that they will rectify this mistake in the near future. The 5th Rangers along with members of the 2nd Btn (with 2 x 75mm mobile half tracks) then advanced on to attack the Maisy battery that was still firing on both Omaha and Utah beaches. The 23 soldiers of the 5th Battalion which reached and re-enforced the 2nd Battalion men at Pointe du Hoc on the 6th June won the Presidential Unit Citation for the 5th Rangers – for the “Deepest penetration of any combat unit on D-day”. (officer commanding) Major Richard Sullivan won the Distinguished Service Cross for three actions in Normandy: the landings on Omaha Beach, the relief of Point du Hoc and the victorious capture of the Maisy Battery.