Towards the late 1800s, Europeans and Americans both worked on the idea of a tire tread. They realized a treaded machine would be useful on rougher terrain. The Holt Manufacturing Company, later renamed Caterpillar, perfected and patented a working tread in 1904.
While engineers experimented developing working treads for tractors their use in war was obvious. In 1903, French artillery captain Léon Levavasseur envisioned an armored tractor with a cannon mounted to the front. Austrian officer Günther Burstyn envisioned a similar device with a rotating gun turret. Science fiction writer H.G. Wells published a whole short story, The Land Ironclads, in 1903 about motorized armor fighting machines. Similar to the countless failed attempts at tractor treads, some work went into their ideas but nobody developed a working machine.
With the outbreak of WWI, armies immediately realized the value of Holt’s tractors. The vast majority of WWI was fought in trenches. Soldiers would try running from their trench to the other, usually unable to break through a barrage of gunfire. However, they reasoned that an armored Holt tractor might work.
By the end of WWI, about 10,000 Holt tractors saw combat. American and English troops used modified Holt tractors from the beginning. The French initially determined to build their own treaded tractor but, by 1915, decided to also use modified Holt tractors.
By the time of WWI, other tractors proved more technologically advanced. However, due to their history as a tractor company, they were available in large quantities. The ability to quickly produce many tractors surpassed technological advantages other manufacturers might offer.
Various allied forces worked throughout the war to create and improve the tank. The word “tank” was the codename for the project of developing a weaponized tractor. Although the French and English tried using technology from their respective countries, Holt tractors proved the least costly and most widely available.
Despite their technological superiority producing motors and cars, the Germans only built one type of tank and deployed only 20 of those. Their tank, the A7V, was enormous and required 18 soldiers to operate. They also used about three dozen captured British tanks.
Tanks did not begin to make a material dent in fighting until the end of the war and, even then, their impact was minimal.
Against the advice of colleagues, a rising officer in the US, Lt. Col. Patton, decided to join the newly formed US Tank Brigade. Between the wars, Americans under Patton continued improving their tank and Germans developed their own Panzer division. However, it was the French who built the largest number of tanks. The Soviets developed a capable tank and built about 5,000 but Stalin eventually executed the head of the project, Mikhail Tukhachevsky. The lack of tanks at the outbreak of WWII cost countless Russian lives though they later redeveloped their tank brigade. Despite the obviousness of the answer in hindsight, various generals argued during the period between the wars whether horses were obsolete.
Whereas tanks developed too late in WWI, they were a central weapon in WWII. Tanks remain a central weapon in all modern armies.