Got something to say to this podcast? Send a voicemail, and you might hear yourself on the next episode!

In the 1890s, Benjamin Holt watched his steam tractors, which weighed 1,000 pounds for every unit of horsepower, sink into the peaty soil of California’s San Joaquin Valley Delta near Stockton. He tried seven-and-a-half-foot wheels, a 46-foot-wide machine and crews laying wooden plank roads before deciding the tractor had to carry its own road. On Thanksgiving Day, November 24, 1904, he bolted redwood slats to chains on steamer number 77 and plowed the mud of Roberts Island. Company photographer Charles Clements said the rolling track looked like a caterpillar, and Holt adopted the name. By 1909 his crawlers sold for $5,500 each, and a bankrupt plant in East Peoria, Illinois grew from 12 workers to 625 in two years.

World War I turned farm machines into artillery tractors hauling six-inch howitzers across the Western Front, and British correspondent Ernest Swinton’s observations of them inspired the first tanks. Peace brought canceled orders, cheap surplus and a costly rivalry with C.L. Best. Holt died on December 5, 1920, bankers took control, and in 1925 the two companies merged as Caterpillar Tractor Co., with Best as CEO until 1951. The episode follows the company to 118,000 employees and more than $67 billion in revenue by 2025, along with the 1999 Clean Air Act case over diesel engines with defeat devices, UAW strikes, and scrutiny of armored D9 bulldozers used by the Israel Defense Forces.

• Britain’s Richard Hornsby and Sons patented a steel-plate tracked vehicle in 1904 with differential braking for steering, then sold the patent to Holt five years later.
• Before the U.S. entered World War I, European governments bought 1,200 Holt tractors for farming and sent them straight to the battlefield.
• Holt and Best spent about $1.5 million in legal fees fighting over track patents between 1907 and 1918.
• The Federal Aid Highway Act of 1921 put $1 billion into road building, and the company pivoted to road equipment to survive.
• The EPA estimated the defeat-device engines produced 1.3 million tons of excess emissions in 1998 alone.