Mexico and the United States each have a constitution and a federal system of government. This fact has led many historians to assume that the Mexican system of government, established in the 1820s, is an imitation of the U.S. model. But it is not.

First published in Spanish in 1955 and now translated by the author and amplified with new material, this interpretation of the independence movement tells the true story of Mexico's transition from colonial status to federal state. Benson traces the Mexican government's beginning to events in Spain in 1808-1810, when provincial...