The Southwestern U.S. has undergone multiple waves of settlement since Europeans began arriving in North America in 1492. First on the scene were the Spanish conquistadors who arrived in present day Arizona and New Mexico by the mid 1500’s. Spanish missionaries soon followed. Later, with the opening of trade routes, the American notion of Manifest Destiny and the acquisition of territory by the U.S. military, American settlers began to arrive. The stories of these settlers, their settlements, and the routes they traveled can be found in the pages below.