The feat of exploration, conquest and defense that Spain carried out, for 300 years, in what is now the United States of America is a capital historical event. Spaniards were the first Europeans to sight the Colorado Canyon, cross the Mississippi River, cross the great plains, enter the deserts of Nevada or founding cities such as Los Angeles, Santa Fe or San Francisco. Long before the United States existed as a nation, Spain had already conquered the Far West and fought or signed treaties with the main Indian tribes that Hollywood films would later make famous. This work includes a list of all Spanish forts, fortified posts, missions and presidios in the United States and Canada.