In 1924, the founder, William Pigott sold a controlling interest in the company to American Car and Foundry Company. However, his son, Paul Pigott reacquired a significant interest in the company from American Car and Foundry Company in 1934.
During World War II, Pacific Car and Foundry’s sales had grown due to an increased demand for steel used in airplanes, airports, bridges, naval ships, highways and other equipment that helped build America’s infrastructure to support the war effort. Pacific Car also sub-contracted for Boeing, building aluminum wingspans for B-17 bombers. During the spring of 1942 the company also built Sherman M4-A1 tanks for the U.S. Army. The company was able to cast almost all the parts for the tanks at its own foundry. Other notable vehicles that were built included the M25 Tank Transporter, known as the Dragon Wagon, and the T28 Super Heavy Tank. Everett-Pacific Shipbuilding & Dry Dock Company was established in 1942 that built ships and other marine products for the US Navy in Port Gardner Bay in Everett. It was bought by Pacific Car and Foundry in 1944
After World War II ended, Pacific Car was a part of the federal government’s Mobilization Planning Program, which meant that it promised to devote 100 percent of its facilities to military production in the event of a national emergency. The company was a prime contractor during the Korean conflict for producing tanks. Pacific Car chose to subcontract many of the necessary parts, boosting smaller businesses in the state. In 1945 Pacific Car purchased the Kenworth Motor Truck Corporation which was named after the stockholders Harry Kent and Edgar Worthington. Kenworth had been producing trucks in Seattle since it was incorporated in 1923. During World War II, Kenworth produced trucks, airplane assemblies and sub-assemblies for the United States military. As the war drew to an end Kenworth shifted attention to production of commercial trucks for the postwar market. In 1956 Kenworth lost independent status and became a division directly under Pacific Car and Foundry.
In 1954, Pacific Car acquired the Dart Truck Company of Kansas City, Missouri, and the Motors Company, of Oakland, California. Dart built primarily heavy off-highway dump trucks and specialty vehicles. Peterbilt had been a major competitor with Kenworth, producing many kinds of trucks and buses. Peterbilt operated as Pacific Car’s wholly owned subsidiary till 1960 following which it was dissolved and made a division of Pacific Car and Foundry.
In the mid 1980s PACCAR's share of Class 8 trucks dropped to about 18% owing to aggressive competition from Trucks which is a subsidiary of Daimler AG and the merged operations of Volvo White and General which forced PACCAR to close Kenworth assembly plant in Kansas City in April 1986 and Peterbilt plant in Newark, California, the following October. PACCAR acquired Trico Industries in 1986 which was a manufacturer of oil exploration equipment based in Gardena, California for $65 million in order to reduce its dependence on the Class 8 Truck market. During the mid-80's PACCAR was negotiating with the Rover Group, for acquiring its British British Leyland truck division. However, Rover management decided to sell the truck division to DAF Trucks which was a Dutch automotive concern. In Dart Truck Company and Wagner Mining Equipment Company was sold in 1984 and 1989 in order to remain profitable. In 1987 PACCAR acquired Al’s Auto Supply and Grand Auto Incorporated which led to its entry into the automotive parts & accessories retail market that gave the company greater ability to weather periods of national economic downturn.
Kenworth truck factory in Renton, Washington was opened on June 4, In 1997 Mark Pigott assumed PACCAR's presidency as Charles Pigott retired in 1997.In 1996 & 1998 the company spent $543 million to acquire DAF Trucks N.V. based in the Netherlands and Leyland Trucks Ltd., an acquisition it first pursued back in the mid-1980s.
Also, in 1998 PACCAR acquired UK-based Leyland Trucks for its light and medium truck (6 to 44 metric tons) design and manufacture capability. With its Peterbilt, Kenworth, and DAF nameplates, PACCAR ranks second in production numbers in the United States and third in production numbers globally in "big rig" truck production; behind Daimler AG in the US market. Other Major heavy-truck competitors include Navistar International and AB Volvo.
