High Quality Content by WIKIPEDIA articles! U.S. Route 6 (US 6), also called the Grand Army of the Republic Highway, a name that honors an American Civil War veterans association, is a main route of the U.S. Highway system, running east-northeast from Bishop, California to Provincetown, Massachusetts. Until 1964, it continued south from Bishop to Long Beach, California, and was a transcontinental route. After U.S. Route 20, it is the second-longest U.S. highway in the United States and the longest continuous highway.