Near this site on December 16–17, 1846, the U.S. 101st Infantry ("Mormon") Battalion under Colonel Philip St. George Cooke peacefully occupied the Presidio San Agustin del Tucson. Organized in Council Bluffs, Iowa, to reinforce General Stephen Watts Kearny's Army of the West during the Mexican-American War, the battalion marched 2,000 miles to San Diego, probably the longest march in U.S. military history. By the time it reached Tucson, it was reduced in numbers and sorely in need of provisions. Although this was Mexican territory, the opposing military forces avoided hostilities and agreed instead to a peaceful barter, trading buttons, clothing, and other items for Mexican grain and salt. The United States flag, the first to fly over Tucson, was posted briefly on December 16, 1846, and the following day the battalion continued its march northward toward the Gila River.