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
Mexican War of Independence square, the zócalo, with the pealing of the Metropolitan Cathedral of Mexico City's bells. In the 1880s, government officials attempted to move the bell that Hidalgo rang in 1810 to gather parishioners in Dolores for what became his famous "grito". Initially the pueblo's officials said the bell no longer existed, but in 1896, the bell, known as the Bell of San José, was taken to the capital. It was renamed the "Bell of Independence" and ritually rung by Díaz. It is now an integral part of Independence Day festivities. Mexican War of Independence The Mexican War of Independence () was