The early years of mining here were turbulent, as explorers and adventurers attempted mining operations. Fur trappers Sylvester Pattie and his son James mined copper and used the underground mines to store furs, and Kit Carson also worked here as a teamster. The Apache Indians regarded this country as their domain, and raids sometimes caused mines and nearby communities to be abandoned. The Spaniards built the Santa Rita fort with thick adobe bricks to protect miners. In 1821 the territory passed from Spanish to Mexican ownership, and in 1853 the region became part of the United States through the Gadsden Purchase, a boundary change that allowed a southern intercontinental railroad route and included some of the richest mineral land in the United States. Mining at Santa Rita continued under various owners but stopped during the Civil War. After the end of the Apache wars, about 1886, conditions improved and miners' safety was guaranteed, though many more years passed before copper was mined profitably in this region. The Santa Rita Mine, named for the small community once located here, is often called the Chino Mine, though the origin of Chino is uncertain and is believed to come from a slang Mexican word for quartz. Today Chino is owned by Freeport-McMoRan Copper & Gold Inc.