The Mexican Frontier, 1821–1846 published by other historians. This work was supplemented by additional primary materials which he discovered in the archives that allowed him to delve further into certain areas. "The Mexican Frontier" examines the southwestern United States, specifically the areas now known as Arizona, California, New Mexico, and Texas, in the twenty-five years between Mexico's independence from Spain and the beginning of the Mexican–American War. This resulted in the transfer of control of the border areas to the United States. In the early days of the Republic of Mexico, these areas comprised its northern border, including the territories of Alta California and
Latin American wars of independence movement against their colonial master, finally ended as a full-fledged civil war. Traditionally, the process is divided into three stages: Patria Vieja, Reconquista, and Patria Nueva. The first uprising against Spanish rule took place in 1809, and criollos in Ecuador set up a junta on September 22, 1810 to rule in the name of the Bourbon monarch; but as elsewhere, it allowed assertion of their own power. Only in 1822 did Ecuador fully gain independence and became part of Gran Colombia, from which it withdrew in 1830. At the Battle of Pichincha, near present-day Quito, Ecuador on May 24, 1822,