The Mexican–American War, followed by the Treaty of Guadalupe Hidalgo in 1848 and the Gadsden Purchase in 1853, extended U.S. control over a wide range of territory once held by Spain and later Mexico, including the present day states of New Mexico, Colorado, Utah, Nevada, Arizona, and California. The vast majority of Hispanic populations chose to stay and become full US citizens. Although the treaty promised that the landowners in this newly acquired territory would enjoy full enjoyment and protection of their property as if they were citizens of the United States, many former citizens of Mexico lost their land in lawsuits before state and federal courts or as a result of legislation passed after the treaty. Even those statutes intended to protect the owners of property at the time of the extension of the United States' borders, such as the 1851 California Land Act, had the effect of dispossessing Californio owners ruined by the cost of maintaining litigation over land titles for years.