Complex sentence: The first Spanish settlers emigrated to New Mexico on July 11,1598, when the explorer Don Juan de Oñate came north from Mexico City to New Mexico with 500 Spanish settlers and soldiers and a livestock of 7,000 animals.
Split into simpler sentences: The first Spanish settlers emigrated to New Mexico on July 11,1598. On this date, the explorer Don Juan de Oñate came north from Mexico City to New Mexico with 500 Spanish settlers and soldiers and a livestock of 7,000 animals.