On Friday January 15, 1847, the Mormon Battalion, a volunteer unit of the Army of the West commanded by Lieutenant Colonel Philip St. George Cooke, crossed Interstate Highway 8 approximately seven miles west of this point while the United States was at war with Mexico. The battalion made its historic march from Council Bluffs, Iowa, to San Diego on the Pacific Coast, a journey of over 2,000 miles regarded as the world's greatest march of infantry. The battalion's supply wagons were the first wheels to traverse this area, now Imperial County, California, opening the first southern route west.