In the 16th Century, the land along the west coast of the United States was explored and settlements were founded by people arriving in ships flying the flag of Spain. Many of the sailors stayed instead of returning to Spain. These Europeans brought many diseases and the local indigenous peoples were greatly affected. Those who survived gathered in small communities, and some lived and worked with the landed Europeans and began to speak Spanish. Between 1697 and 1821, Spain governed and colonized what is now called Mexico and started investigating the coastal land along the west coast of North America. At the same time, Spanish missionaries arrived in the newly explored areas and began converting the indigenous tribal people to the Christian Catholic faith. In 1848, the United States defeated Mexico in the Mexican American War and claimed Mexico and California.
In 1849, the California Gold Rush began with the discovery of gold in the north of California. People from all around the world began pouring into California. Not many of them became rich, but the cities grew bigger and bigger and the ones who remained learned Spanish and adapted to the communities of Spanish speaking people.
Today, there are more Christian Catholics in California than anywhere else in the United States. Settlements around small villages grew and became San Diego, Los Angeles, and San Jose, and now they are three of the biggest and most prosperous cities of California.
In California you can find cultural elements from many different countries, but the Spanish inheritance is visible everywhere.