Roman Law in the Water, Mineral and Public Land Law of the Southwestern United States

Abstract

Much of the arid zone of the Southwestern United States was under Spanish (and later, Mexican) rule until the fourth and fifth decades of the 19th century. This includes the present states of Texas, New Mexico, Arizona, California, Utah, Nevada, and parts of southern Colorado. Only Texas, New Mexico, and California were populated before the change of sovereignty. Texas had about 36,000 inhabitants in 1836, 24,000 of whom were English-speaking. The populations of New Mexico (55,000) and of California (3,000) were Spanish-speaking. There were also small Spanish-speaking settlements in Arizona and in Colorado before 1848. The present legal systems of these states are based on the common law, which was introduced in Texas in 1840, in California in 1849, and New Mexico in 1876. To a greater or a lesser extent, these legal systems respect rights acquired under Spanish and Mexican law. Mexican property rights are also protected by the Treaty of Guadalupe Hidalgo (1848). Until 1821, the law applicable in the settled areas of the American Southwest was what is commonly called the derecho castellano e indiano, i.e., the law specifically enacted for the ultramarine possessions of the Spanish Empire, supplemented by the law of Castile. After Mexican independence (September, 1821), Mexican central legislation, and (after 1824) Mexican state legislation was superimposed on this corpus of Spanish imperial and Royal Castilian law, but neither Mexican water law nor Mexican mineral law were (as such) codified or even substantially modified in the few decades of Mexican rule in what is now the Southwestern United States.