On the eve of the struggle for independence from Spain the viceroyalty of New Spain (Mexico) constituted a vast area extending from the Caribbean to the Pacific and from the borders of Guatemala and Chiapas to the huge Eastern and Western Internal Provinces, including the territory later incorporated as the south-western United States. The viceroyalty, with a population in 1814 of 6,122,000 (the United States in 1810 had a population of 7,240,000) accounted for over one-third of the total population of the Spanish overseas empire. Mexico City, the viceregal capital, was the largest city in North or South America and, with a population in 1811 of 168,811, after Madrid, the second largest city in the empire.

New Spain was also by far the richest colony of Spain. Its trade through the main port of Veracruz from 1800 to 1809 amounted to an annual average of 27.9 million pesos and in the next decade, between 1811 and 1820, to an annual average of 18 million pesos, divided equally between exports and imports. The colony's total output of goods and services stood in 1800 at approximately 240 million pesos, or roughly 40 pesos per capita. This was only half the per capita production of the United States, at that time, for example, but considerably more than that of any other American colony, Spanish or Portuguese. Agriculture and livestock, which employed approximately 80 per cent of the total labour force, produced about 39 per cent of national resources; manufacturing and cottage industries produced about 23 per cent of total output; trade accounted for 17 per cent; mining for 10 per cent; and the remaining ii per cent came from transportation, government and miscellaneous sources.