One Week after the Treaty of Guadalupe Hidalgo;  officially entitled the Treaty of Peace, Friendship, Limits,  and Settlement between the United States of America and the Mexican Republic, was signed, gold was found on California land.  Once a property of Mexico, and now an  American state.  Here we see a group of Mexican mercenaries, employed by president James K. Polk, guarding a U.S. owned, mine in California .