Territory with different but partially overlapping boundaries. The Confederate boundaries split New Mexico along an east–west line, the 34th parallel north, allowing for a single state connection from Texas to the Colorado River. This would give the Confederacy access to California and the Pacific coast. The Union definition split New Mexico along a north–south line, the 32nd meridian west from Washington, which simply extended the boundary between Colorado and Utah southward. The Union plan eventually became reality, and this created the quadripoint at the modern Four Corners. After the split, New Mexico resembled its modern form, with only slight differences. Surveying the boundaries After the Civil War, efforts began to survey and mark the actual borders. In 1868, the General Land Office (GLO) had Ehud N. Darling survey and set markers along the border between the Colorado and New Mexico Territories (the 37th parallel north); this border over time has become known as the "Darling Line". In 1875, another GLO surveyor, Chandler Robbins, surveyed and marked the border between the Arizona and New Mexico Territories (the 32nd meridian west of Washington). Robbins began near the Mexico–United States border, and worked his way north marking the border every so often. Near the 37th parallel north he intersected the Darling Line, and here he erected a sandstone shaft. This sandstone shaft marked today's location of the Four Corners Monument. In 1878, Rollin J. Reeves surveyed and marked the border between the newly created State of Colorado and the Utah Territory. Reeves located the sandstone shaft marker placed by Robbins at today's Four Corners Monument. He then began to survey and mark the border between Colorado and Utah from this point northward. In 1901, Howard B. Carpenter surveyed and marked the border between Arizona and Utah, completing the survey of borders making up the Four Corners Monument. The results of these surveys and the markers placed were later accepted as the legal boundaries between the various states. The marker's transformation into a monument By 1899, the sandstone shaft marker placed by Chandler Robbins in 1875 had been disturbed and broken, so it was replaced with a new stone by two U.S. surveyors, Hubert D. Page and James M. Lentz. In 1912, a simple concrete pad was poured around the marker. The first modern Navajo government convened in 1923 in an effort to organize and regulate an increasing amount of oil exploration activities on