Caterpillar introduced the Challenger range of agricultural tractors as the result of several development programs over a long period of time. The program started in the 1970s and involved both D6-based units and Grader power units. A parallel program was also developing wheeled high hp tractors based on using the articulated loading shovel chassis was latter merged with the crawler team. The result was the Challenger Tractor and the "Mobi-Trac" system.

The Challenger has been marketed in Europe as Claas machines since 1997, with Caterpillar marketing the Claas built Lexion combine range in the USA. Claas and Caterpillar formed a joint venture, Claas Omaha, to build combine harvesters in Omaha, Nebraska, USA under the CAT brand. In 2002, Cat sold its stake to Claas, and licensed the use of CAT and the CAT yellow livery to Claas. They are marketed as Lexion combines now.

Also in 2002, Caterpillar sold the Challenger tracked tractor business to AGCO and licensed the use of the Challenger and CAT names and livery to them. This ended Cat's venture into agriculture.