The Mexican Frontier is the book for those of us who think the American West was “unsettled” before the United States expanded into and past the Rocky Mountains in the mid-1800s. Its author, noted historian David J. Weber, reminds us that Spain had claimed what is now  Texas, New Mexico, Arizona, and California, in the 1500s, long before the various British attempts to colonize the East Coast.

When Mexico declared its independence from Spain in 1821, what is now known as the American Southwest came under its jurisdiction. The Mexican Frontier 1821-1846 is a comprehensive look at the  the region between 1821 and 1846, when it was acquired by the United States as a result of the Mexican War.

This book fills an important gap in our knowledge of North American history. Weber not only provides a good overview of Mexican policy and how it affected the country’s Northern Frontier, he also points out the similarities and differences between Texas, New Mexico, and California, both in terms of how government policies were interpreted and enforced and how the different regions reacted to them. This discussion was particularly helpful to me in clarifying the connections between events in Texas and in New Mexico in the 1830s and 40s. It’s been foundational to my research for upcoming novels, especially as I dive into the complexities of the New Mexico Tax Revolt in the 1830s.

If you want to understand the history of Texas, New Mexico, Arizona, and California prior to the American takeover, I recommend that you read this very readable book.