When the United States went to war against Mexico in 1846, many Apache bands promised U.S. soldiers safe passage through their lands. When the U.S. claimed former territories of Mexico in 1846, "Mangas Coloradas" signed a peace treaty with the nation, respecting them as conquerors of the Mexicans' land. An uneasy peace between the Apache and the new citizens of the United States held until the 1850s. An influx of gold miners into the Santa Rita Mountains led to conflict with the Apache. This period is sometimes called the Apache Wars.