Juan Bautista de Anza, a Spanish explorer and military leader, embarked on a significant expedition from New Spain to find suitable land for a military and settlement outpost in what is now California. At this time, the Spanish Empire sought to consolidate its foothold in Alta California, which was largely unmarked by European settlement. After a long journey, de Anza and his group arrived in the picturesque area now known as San Francisco. De Anza specifically chose a site near the wharf at the mouth of the San Francisco Bay, which presented natural advantages in terms of navigation and defense against potential threats from other colonial powers.

This strategic decision marked the beginning of the establishment of the Presidio of San Francisco, which would grow to be a significant military base for the Spanish and later the United States. The location was chosen for its topographical benefits, including hills that could serve as lookout points and a central coastline that was conducive to maritime engagements. Upon evaluating the site, de Anza noted the availability of fresh water and fertile land, key factors in sustaining a permanent settlement. These observations not only influenced Spanish colonization strategies but also altered the demographic landscape of the region.

De Anza returned to New Spain to report his findings, eventually leading to an increased Spanish presence in the region with the establishment of various missions and presidios that followed. His expedition paved the way for the growth of what would become one of America's major cities.