The Caterpillar brand evolved from the Holt and Best makes of track-laying tractors. Benjamin Holt produced his first steam-powered "crawler" in 1904, and produced further petrol-engined models in 1906-8. By 1915, Holt tractors were being used by the Allies in W.W.I. In the years after the war, Daniel Best continued development of crawlers, culminating in his 1921 Best 30 Tracklayer, with an enclosed cab and bulldozer blade.
At this time, there was a considerable amount of litigation on-going concerning track-layer patents and two names kept cropping up, Holt & Best. Holt held a patent which enabled him to charge a licence fee to other crawler manufacturers, including Monarch and Cletrac. Most of Holt's production was for the military while Best supplied the agricultural market. In 1925, the two companies merged to form the Caterpillar Tractor Company. Holt had in actual fact bought out Daniel Best in 1908, but then had to compete with his son, Leo Best!
The first new model, the Caterpillar Twenty, went into production in 1927 and ran until 1933. In 1955, the Model 15 was introduced, which with the original 60, 30 and Two Ton, took its range to five. In 1931, the new Model 65 rolled off the production line in Illinois and this year also saw the change from the previous grey colour to the new Highway Yellow livery, seen as a means of brightening up the great Depression, and also for visibility on road construction projects. This has since become a standard colour for lots of construction equipment, not just Caterpillar products.
New diesel-engined variants, using Rudolph Diesel's initials, the RD8, RD7 & RD6 models went into production in 1935, followed by the RD4 in 1936. In 1938, the smallest crawler in the range was introduced, the D2 being suitable for 3 or 4-furrow ploughs. Larger models followed, with the D7 and D8 being used on the huge farms of the mid-West. By the late 1940s, the US Forestry Service were using machines such as the Cletrac Forty crawler with an after-market blade fitted to the front, and this coupled with W.W.II, marked a change of emphasis from agriculture to construction in the post-war years.
World-wide expansion followed with Caterpillar GB set up in 1950 and a joint venture with Mitsubishi in Japan in 1963. However, global recession in the 1980s cost Caterpillar dear and towards the end of that decade, production diversified and moved back towards agriculture. Product development continued with the advent of the rubber-tracked Challenger range in the 1990s, and Caterpillar acquired Peterborough based Perkins engines in 1997, a name synonymous with many manufacturers of tractors.