text: 20th century On Thanksgiving Day, November 24, 1904, Holt successfully tested the first workable track-laying machine, plowing soggy San Joaquin Valley Delta farmland. Company photographer Charles Clements was reported to have observed that the tractor crawled like a caterpillar, and Holt seized on the metaphor. "Caterpillar it is. That's the name for it."
  On April 22, 1918, British Army Col. Ernest Dunlop Swinton visited Stockton while on a tour of the United States. The British and French armies were using many hundreds of Holt tractors to haul heavy guns and supplies during World War I, and Swinton publicly thanked Holt and his workforce for their contribution to the war effort. During 1914 and 1915, Swinton had advocated basing some sort of armored fighting vehicle on Holt's caterpillar tractors, but without success (although Britain did develop tanks, they came from a separate source and were not directly derived from Holt machines). After the appearance of tanks on the battlefield, Holt built a prototype, the gas-electric tank, but it did not enter production.
  On January 10, 1920, a major fire on Main Street threatened an entire city block. At about 2 a.m., a blaze was discovered in the basement of the Yost-Dohrmann store, which was gutted, and adjacent businesses were damaged by flames and water. Damage was estimated at $150,000.
  By 1931, the Stockton Electric Railroad Co. operated 40 streetcars over  of track.