Back to 9000 B.C., San Diego belonged to the California coastal region. There living people were first Americans but now they are called San Dieguito. During 1000 B.C., there were living Indians. In 16 century, Spanish were also migrated over here. Cabrillo was first European who invented San Diego while he was searching for the path to link Atlantic and pacific oceans. He discovered it by the name of San Miguel. He came to this place on September 28, 1542. For many decades, it was ignored by visitors. After sixty years, another explorer came here and renamed it as San Diego. Spanish were not interested in settling the California so this region ignored for many years again. The colonization did not begin in next 167 years.
When food disaster came in Loreto near to San Diego, Indian people died over there. During this march, Serra and Portolá came to San Diego. Portola returned to Monterey Bay with the group to continue March but Serra stayed there. He liked its beauty. On July 16, 1769, first California mission was started named San Diego de Alcala. In 1846, its 58000 acres were granted to Don Santiago Arguello by the governor of Mexico. At that time, this town had the population of 350 and was known as an old town. Due to the war between California and Mexico at that time, San Diego was covered by military forces. San Diego established as the first Spanish mission till the end of war. It became part of United States. Due to the affiliation with the United States, it would be at the boom. But the fact was not so. Its population dropped by half at the end of civil war.
Alonzo Horton and establishment of the city:
San Diego was changed into the new city by Alonzo Horton. He was a rich trader and landowner. He was living in San Francisco and built a city named Hortonville. He wanted to discover New San Diego city. He bought 960 acres to make New San Diego city because it was his dream to make a new city. He was a young man with this ambition while he heard about San Diego near California. During his interview, he told about to go to San Diego to make a new city. In next 20 years, San Diego economy was at its boom. During the mid-1880s, a rail line was established to connect San Diego with East. Its population became high and economically established.