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
Afro-Mexicans in the Mexican War of Independence Afro-Mexicans in the Mexican War of Independence The history of Africans in Mexico has not been well documented or recognized by the government and society. The Spanish relied upon slavery to expand their empire and to increase their wealth, and during the 16th and 17th centuries, African slaves were brought to Mexico to toil in sugar fields and work in underground mines. Estimates vary, but somewhere between 200,000 and 500,000 slaves were brought to Mexico during the colonial expansion. Over the years this bloodline has been absorbed into the population and the contribution of Afro-Mexicans has largely been forgotten. During