The Mexican Cession of 1848 is a historical name in the United States for the region of the modern day southwestern United States that Mexico ceded to the U.S. in the Treaty of Guadalupe Hidalgo in 1848, it had not been part of the areas east of the Rio Grande which had been claimed by the Republic of Texas, though the Texas annexation resolution in which year,incorporation of the Republic of Texas into the United States of America, which was admitted to the Union as the 28th state, had not specified the southern and western boundary of Texas?
Mexican Cession The Mexican Cession of 1848 is a historical name in the United States for the region of the modern day southwestern United States that Mexico ceded to the U.S. in the Treaty of Guadalupe Hidalgo in 1848. It had not been part of the areas east of the Rio Grande which had been claimed by the Republic of Texas, though the Texas annexation resolution two years earlier had not specified the southern and western boundary of Texas. The Mexican Cession (529,000 sq. miles) was the third largest acquisition of territory in US history. The largest was the Louisiana Purchase, with some 827,000 sq. miles, followed by the acquisition of Alaska (about 586,000 sq. miles).
Trans-Pecos The Trans-Pecos, as originally defined in 1887 by the Texas geologist Robert T. Hill, is the portion of Texas that lies west of the Pecos River. The term is considered synonymous with "Far West Texas", a subdivision of West Texas. The Trans-Pecos is part of the Chihuahuan Desert, the largest desert in North America. It is the most mountainous and arid portion of the state, and most of its area (outside the city of El Paso) is vast and sparsely populated, comprising seven of the ten largest counties by area in Texas. The area is known for the natural environment of the Big Bend and the gorge of the Rio Grande, part of which has been designated a National Wild and Scenic Rivers System. With the notable exceptions of Big Bend Ranch State Park and Big Bend National Park, the vast majority of the Trans-Pecos region consists of privately owned ranchland. The vast majority of the region's population reside in the El Paso metropolitan area.