Prior to the establishment of the United States Numbered Highways in 1926, the main Los Angeles-Sacramento route, pre-1964 Legislative Route 4, ran from Manteca to Stockton via French Camp (later US 99W). At French Camp, pre-1964 Legislative Route 5 split to the southwest to reach the San Francisco Bay Area via Altamont Pass. The Lincoln Highway used Route 4 from Sacramento to French Camp and Route 5 over Altamont Pass.