United States Army Rangers are elite members of the United States Army. Rangers have served in recognized U. S. Army Ranger units or have graduated from the U. S. Army’s Ranger School.  The term “Ranger” was first used in North America in the early 17th century; however, the first ranger company was not officially commissioned until King Philip’s War (1676) and then they were used in the four French and Indian Wars. Rangers also fought in the American Revolution, the War of 1812, and the American Civil War.
It was not until World War II that the modern Ranger concept was conceived, authorized by General George C. Marshall in 1942. The six battalions of the modern Rangers have been deployed in wars in Korea, Vietnam, Afghanistan, and Iraq, and saw action in several conflicts, such as those in Panama and Grenada. Of the current active Ranger battalions, two—the 1st and the 2nd—have been in service since reactivation in 1974.  The 3rd Ranger Battalion and the headquarters of the 75th Ranger Regiment were reactivated in 1984.
The 75th Ranger Regiment is now a special operations combat formation within the U. S. Army Special Operation Command (USASOC). The Ranger Regiment traces its lineage to three of six battalions raised in WWII, and to the 5307th Composite Unit (Provisional)—known as “Merrill’s Marauders,” and then reflagged as the 475th Infantry, then later as the 75th Infantry. The Ranger Training Brigade (RTB)—headquartered at Fort Benning, GA—is an organization under the U. S. Army’s Training and Doctrine Command (TRADOC) and is separate from the 75th Ranger Regiment.
It has been in service under various names and Army departments since World War II. The Ranger Training Brigade administrates Ranger School. Successful completion of this 61-day course is required to become Ranger qualified and to wear the Ranger Tab. When the American Revolution began, Major Robert Rogers allegedly offered his services to General George Washington. Fearing that Rogers was a spy, Washington refused. An incensed Rogers instead joined forces with the Loyalists and fought for the crown.
Not all of Rogers’ Rangers went with him, however, including such notable figures as Israel Putnam. Later on during the war, General Washington ordered Lieutenant Colonel Thomas Knowlton to select an elite group of men for reconnaissance missions. This unit was known as Knowlton’s Rangers, and is credited as the first official Ranger unit (by name) for the United States. This unit, however, carried out intelligence functions rather than combat functions in most cases, and as such are not generally considered the historical parent of the modern day Army Rangers.
Instead, Knowlton’s Rangers gave rise to the modern Military Intelligence branch (although it was not a distinct branch until the 20th century). [ The most famous Rangers of the American Civil War fought for the Confederate States Army. In January 1863, John S. Mosby was given command of the 43rd Battalion, Partisan Ranger. Mosby’s Rangers became infamous among Union soldiers due to their frequent raids on supply trains and couriers. Their reputation was heightened considerably when they performed a raid deep into Union territory and captured three high-ranking officers, including Brigadier General Edwin H.
Stoughton. Weeks after the surrender of the Confederate Army Mosby disbanded his unit rather than formally surrender. Also a famous Confederate commander, Turner Ashby led a cavalry company known as the Mountain Rangers, who became known for their ability to harass Union soldiers. The most successful attacks against Mosby’s Rangers were carried out by the Union Army’s Mean’s Rangers. Mean’s Rangers became famous when they successfully captured General James Longstreet’s ammunition train. They later fought and captured a portion of Mosby’s force.
In January 1941, during World War II, Colonel Dudley Clarke met American Colonel William J. Donovan during a strategic tour of the Mediterranean. During the Second World War, Major General Lucian K. Truscott, the US Army Liaison, saw the capabilities of the British Army’s SAS (Special Air Service) Commandos. He immediately sent a proposal stating "We undertake immediately an American unit along the lines of the British Commandos” on 26 May 1942 to General George Marshall. The US Army then began a program to make a commando unit for the US Military.
The telegram Truscott sent out was received by Major General Russell P. Hartle, the commander of all US Army forces in Northern Ireland. Now that the first battalion of commandos was authorized, a name for the new commando unit would be chosen. Truscott picked Rangers because "The name Commandos rightfully belonged to the British. ” Rangers were a part of the earliest stages in colonizing America so it seemed to be an exceptional choice.  Now the General was tasked to find a commander worthy enough to lead the Ranger battalion.
General Hartle decided that his own aid-de-camp, Captain William Orlando Darby, a graduate of West Point with amphibious training, was the ideal choice. This decision was highly approved by General Truscott who rated Darby as “outstanding in appearance, possessed of a most attractive personality…. and filled with enthusiasm”. usands of applications poured in from the Army in Northern Ireland. Most came from units such as the 1st Armored Division and the 34th Infantry Division. The Officers would be hand picked by Darby to ensure maximum unit efficiency.
He then brought in the applicants he chose. After a stressful and grueling weeding out of his new applicants at Carrick Fergus, NI, the first battalion officially activated on 19 June 1942. In May 1942, the 1st Ranger Battalion was sanctioned, recruited, and began training under the British Commandos in Carrickfergus, Northern Ireland. Their courage is evident from the observation that “of 500 volunteers who first formed the Rangers at Carrickfergus, only 87 were alive by the end of the war. “percent of the original Rangers came from the 34th Infantry Division.
Together with the ensuing 3rd and 4th Ranger Battalions they fought in North Africa and Italy commanded by Colonel Darby until the Battle of Cisterna (29 January 1944) when most of the Rangers of the 1st and 3rd Battalions were captured. The remaining Rangers were absorbed into the Canadian-American First Special Service Force under Brigadier General Robert T. Frederick. They were then instrumental in operations in and around the Anzio beachhead.  info on this paer is courtesy of http://en. wikipedia. org/wiki/United_States_Army_Rangers#American_Revolution