Although a few different Army branches have laid claim to the roots of armored cavalry, no other location did more to shape its dominance than Fort Knox, and at no other time than World War II. In the 1920s, however, the path to Fort Knox didn't exist.
Coming off the heels of World War I, the War Department struggled to define a clear purpose for a mechanized force, at first considering tanks as little more than infantry support weapons. By the 1920s, as automotive developments and innovative uses by other nations necessitated a change in thinking, Army leaders created the Mechanized Force.
All that changed in 1931 when Army Chief of Staff Gen. Douglas MacArthur implemented a new policy that enabled the cavalry to build a mechanized unit. The old Mechanized Force disbanded, and under efforts by Col. Daniel Van Voorhis, Fort Knox was established as the new home for mechanized cavalry. Van Voorhis later said he favored Fort Knox because "it would not be dominated there by the chief of any branch," according to History of the Armored Force.
The news reached members of 1st Cavalry Regiment, who had been operating as a horse cavalry unit at Fort D.A. Russell in Texas. During a parade on Dec. 14, 1932, the troopers participated in their last posting with horses, where they dismounted and passed in review, saluting the horses. They arrived at Fort Knox in January 1933, where they became part of 7th Cavalry Brigade (Mechanized), which pioneered the foundational principles for armor.
By 1939, under the leadership of Van Voorhis and Adna Chaffee Jr., 7th Cavalry Brigade (Mechanized) developed the framework for later armored doctrine.
For Dr. Robert Cameron, Armor Branch historian at Fort Benning, who served as the branch historian at Fort Knox from 1996 to 2011, development of the armored force in the 1930s under Van Voorhis and Chaffee became critical to what would soon follow.
"Timing is everything," Cameron said. "Armored force leaders in World War II built on a precedent that began in the 1930s."
World War II changed the world of armored cavalry.
The war cemented Fort Knox as the center for all armored development, promoted the post's largest growth in its history, and accelerated the development of doctrine, organization, training, materiel, leadership, personnel and facilities, according to Cameron.
"When we talk about the center of gravity for armored force … in World War II … in July of 1940 -- that's when the armored force is created -- Fort Knox encompassed some 864 buildings," Cameron said. "By August of 1943 -- that's not the end of the war, that's just by August of 1943 alone -- that number had risen to 3,820," a fourfold increase.
Cameron explained that facilities were not the only growth happening at Fort Knox -- the area grew as well, from about 30,000 acres in 1940 to 106,861 in 1943.
"This gives you an idea, in just a few short years, how rapid this growth was," Cameron said. "The Army would not have invested and pushed this much expansion if there wasn't a perceived need for it.
"That also tends to underscore the importance that the Army placed on the armored force," he continued. "This is a period of mass expansion of the armored force. In terms of just armored divisions, the force will go from the initial two to a grand total of 16 by war's end."
When leaders prepared to stand up the tank force, they looked at everything: from how the tanks were designed to why, and for what end; they looked at other armies' tanks and how they were using them -- in particular, what Germany was doing with its Panzer divisions.
"Early on, doctrine is shaped by the experiences of 7th Cav Brigade Mechanized, but it's also shaped by information that we were able to get on how the Germans are conducting operations overseas," said Cameron. "We have lots of lessons learned from the French experience, the British are sharing information with us; later on the Russians will share some information … and once we enter the conflict, then of course the shaping influence is our own combat experience."
In preparation for the war with Germany and Italy, the American leaders charged with standing up an Armored Force had converged in one location to build the organization from the ground up, as quickly as possible.
"All of this [information] is being fed into Fort Knox," he said. "People there are figuring out how to put it all together in a way that makes sense, and how best to apply it to these organizations. Not surprisingly, the very first armored division structure looks suspiciously like a Panzer division."
What armored force leaders realized over time, however, was that they didn't need to go head-to-head with the German Panzer divisions, playing to Adolph Hitler's strength. They didn't need to shape their force into one that matched Germany's force.
From this mass force of brain power and determination came concepts of using tanks to attack the weak rear echelons of the German force -- the headquarters elements, the supply lines, the German machine gun bunkers keeping Infantry Soldiers pinned down.
"All the doctrinal concepts to shape how armored units are going to be employed in combat is being developed at Fort Knox," said Cameron. "The second thing is, most of the Soldiers that are going to serve in armored units are being trained directly at Fort Knox."
The growth in personnel alone created its own problems. According to Cameron, the massive deluge of people operating at Fort Knox caused the installation to be considered one of the most hazardous traffic areas in the nation.
By war's end, the lessons learned would shape the next generation of tankers as they faced a Cold War and eventually the Korean War. By war's end, the armored force and Fort Knox would leave an indelible mark on the look and feel of the American military for generations afterward.
After the war's end, another huge change came to Fort Knox.
"The sad thing is just how quickly that armor force that was created vaporizes," said Cameron. "By 1948, those 16 armored divisions would become only one armored division. It was worse for the infantry, but that mass creation is replaced by a giant sucking sound in 1945 and '46.
"That was the sound of the Army vaporizing, demobilizing and going home."