Located in the Gulf of Mexico, at the border with Mexico, between New Mexico, Oklahoma, Arkansas, and Louisiana, Texas is the second most populous (after California) and the second-largest of the 50 states (after Alaska) of the United States. In Pre-Columbian period, in the area were developed three major indigenous cultures, which reached their developmental peak before the first European contact: the Pueblo, the Mississippian culture, and the civilizations of Mesoamerica. In 1528, after the arrival of Álvar Núñez Cabeza de Vaca, "half the natives died from a disease of the bowels". During the next 150 years Europeans have ignored the area, then occupied by French (1684-1689), Spanish(1690-1821), and Mexican (1821-1836). Becoming republic after the Declarationof Independence in 1836, it was admitted to the Unionas the 28th state in 1845, and during the Civil War joined the ConfederateStates.