Feature Article The History of the Presidio Today, the Presidio in San Francisco is associated with the large military complex that was built between the two world wars. But the site actually has a rich history that goes back more than a thousand years. It was the home to a native people known as the Ohlone when the Spanish arrived in 1776. The Spanish built missions, houses, and a military garrison, known as a "presidio" in Spanish. At that time, the Presidio was the northernmost settlement of Spanish-held territory in the West, at the end of a long line of Spanish barracks and missions running all along the coast from Mexico. The purpose of the Spanish presidios was to maintain law and order in the new Spanish settlements and to protect the coast from any British or Russian invasion. The Spanish presence eventually grew to five missions and four pueblos, or towns, in the Bay Area. In 1821, after the Mexican Revolution, the Presidio was occupied by Mexican soldiers. But the scarcity of local resources prompted one commander, General Vallejo, to abandon the Presidio in favor of another headquarters near Sonoma. During the war with Mexico, American soldiers landed in 1846 and captured the Bay Area, including the Presidio. Two years later, California was formally transferred by treaty from Mexico to the United States. By then, many immigrants had settled in and around the Presidio, including Russians, Chinese, and Japanese. The Gold Rush of California greatly boosted the population growth of the San Francisco settlement. The Presidio became an American command center for frequent raids against Indian tribes throughout the Northwest. After the San Francisco earthquake of 1906, the Presidio set up a huge tent camp for the thousands of refugees made homeless by the destruction in the city. Though hardly touched by the Civil War, the Presidio was expanded during the First World War. But its heyday was World War II. After the Japanese attack on Pearl Harbor, the Presidio became the headquarters for the Western Defense Command. Its hospital became the largest debarkation hospital in the country for casualties of the Pacific theater. After the war, the Presidio was the headquarters of the Sixth U.S. Army, housing a complex of some 350 buildings. Only in 1989, near the end of the Cold War, did the Pentagon decide to close the Presidio and transfer the buildings to the National Park Service.