In addition to the sale of land, the treaty also provided for the recognition of the Rio Grande as the border between the state of Texas and Mexico.  Land boundaries were defined by a survey team composed of designated representatives from Mexico and the United States and published in three volumes as The United States and Mexican Boundary Survey. On December 30, 1853, the countries changed the limit of the initial limit by mutual agreement by increasing the number of border marks from 6 to 53.  Most of these markers were simply piles of stones.  Two subsequent conventions, 1882 and 1889, clarified the boundaries, as some of the marks had been moved or destroyed.  Photographers were called in to document the position of the markers. These photographs are available in record Group 77, Records of the Office of the Chief Engineers, in the National Archives. The Treaty of Guadalupe Hidalgo, which officially ended the Mexican-American War (1846-1848), was signed on February 2, 1848 in Guadalupe Hidalgo, a city north of the capital where the Mexican government had taken refuge with the advance of American forces. Mexico ceded 55% of its territory to the United States, including parts of present-day Arizona, California, New Mexico, Texas, Colorado, Nevada and Utah. On May 30, 1848, as the two countries exchanged ratifications of the Treaty of Guadalupe Hidalgo, they continued to negotiate a three-article protocol to explain the changes. The first article stated that the original Article IX of the treaty, although it had been replaced by Article III of the Louisiana Treaty, would still confer the rights set out in Article IX. The second article confirmed the legitimacy of land uses under Mexican law.