Map of the Sunshine Highway.
The National Highways Association (NHA) was established in 1911 to promote the development of an improved national road network in the United States. Under the slogan "Good roads for everyone!" the NHA advocated the building and permanent maintenance by the federal government of a system of 50,000 miles (some 80,500 kilometers) of highways. This map, issued by the NHA in 1915, shows the Sunshine Highway, proposed by the Sunshine Highway Association and endorsed by the NHA. The projected route runs from the U.S.--Canada border in Washington State to Nogales, Arizona, on the U.S.--Mexi...