Clessie Cummins, founder of the Cummins Engine Co., improved on and designed new diesel engines. Cummins also virtually eliminated brake failures in steep downhill travel with his engine compression-release brake—known today as the “Jake Brake”—that he designed and patented.

Leland James founded Consolidated Truck Lines in 1929, building a transcontinental network through acquisitions and fleet standardization. When no one would build his lightweight cabover trucks, he launched Freightliner in 1942. His push for custom designs and double trailers reshaped trucking, and his legacy still drives the industry today.

In 1938, Frederick McKinley Jones was charged with a mission that would revolutionize the refrigeration industry. From humble beginnings, Thermo King Corporation emerged as a titan in the trucking industry. Known for pioneering portable air-cooling units for trucks and prioritizing innovation, Jones’s legacy continues to shape the modern landscape.

In 1917, Edgar Worthington and Captain Frederick Kent revived Gersix Motor Company, former division of Gerlinger Company, later joined by Kent’s son Harry. In 1923, they renamed it Kenworth. They pioneered diesel trucks during the Great Depression and grew Kenworth into a leader known for iconic models like the W-900 and K-100.

The Mack Brothers, founders of Mack Trucks, initiated a history of truck development unparalleled in the industry, and established a company whose reputation for tough, high-quality products has since become “part of the language.”