The 1848 Treaty of Guadalupe Hidalgo ending the U.S.-Mexican War expanded the United States to the Pacific Coast. It conferred U.S. citizenship on former Mexican nationals in the new territories, protecting their “property of every kind.” Yet many families who had received land decades or centuries earlier from Mexico or Spain found their ownership contested by new claimants. To settle disputes, Congress passed private acts and created a temporary Court of Private Land Claims (1891–1904), but many Mexican Americans lacked documents required to prove their claims.