On June 23, 1846 the United States had officially overtaken California from Mexico with the signing of the Treaty of Guadalupe Hidalgo.
After signing the Treaty of Guadalupe Hidalgo, the U.S. respected most prior claims to land; however, there were disbanded claims over large swaths of lands held by rich large land-owning Mexicans. Many lands were vested title to American squatters who had claimed the land. The change in land and title forced the newly created US to alter its legal system in order to rightly answer the claims of land issued by both Mexicans and U.S. citizens alike. The United States disbanded the Spanish civil law and replaced it with English common law.
Squatting rights helped establish the ability for non owning land users to be granted property ownership after extended use of the land. Because much of the land that the United States occupied was unclaimed, squatting rights was a method in which a significant amount of land was claimed. Establishing a valid case for squatters rights requires the non owning land user to use the property in a productive and useful manner.