Friday 12th October 1979

The final section of the Canada to Mexico freeway, Interstate 5, was dedicated near Stockton, California. Representatives of the two neighboring nations attended the dedication to commemorate the first contiguous freeway connecting the North American countries.It travels through the states of California, Oregon, and Washington, serving the largest cities on the U.S. West Coast, including Seattle, Portland, Sacramento, Los Angeles, and San Diego. The highway’s southern terminus is the Mexican border and its northern terminus is the Canada–US border; it is currently the only continuous Interstate highway to touch the U.S. borders with both Canada and Mexico. Upon crossing the Mexican border at its southern terminus, Interstate 5 continues to Tijuana, Baja California as Mexico Federal Highway 1. Upon crossing the Canada–US border at its northern terminus, it continues to Vancouver as British Columbia Highway 99.

Interstate 5 was originally created in 1956 as part of the Interstate Highway System, but was predated by several auto trails and highways built in the early 20th century. The Pacific Highway auto trail was built in the 1910s and 1920s by the states of California, Oregon, and Washington, and was later incorporated into U.S. Route 99 (US 99) in 1926. Interstate 5 largely follows the route of US 99, with the exception of a portion in the Central Valley of California. The freeway was built in segments between 1956 and 1979, including expressway sections of US 99 that were built earlier to bypass various towns along the route.