1921 – The nation’s largest county fair starts out as a simple commercial industrial show alongside the railroad siding.
1922 – Moving quickly, the City of Pomona purchased a 43-acre beet and barley farm and designated the land as the permanent home of the official “Los Angeles County Fair,” organized to promote agricultural, horticultural and animal husbandry interests of the great Southwest.
1933 – Pari-mutuel wagering was legalized in California, and the Fair allowed fans to bet on horse-racing. Cowboy actor Monty Montana wed Louise Archer in front of the racetrack grandstand.
1935 – The Fair incorporates a Wine Competition into the program.
1942 – World War II brought a halt to the Fair for six years as the grounds were taken over by the U. S. Army. A community of 5,428 Japanese Americans were housed in 420 temporary buildings before being relocated to other parts of the country.
1943-1944 – The army used the grounds as a desert training center and Ordnance Command shop.