The written history of Los Angeles city and county began with a small Mexican town that changed little in the three decades after 1848, when California became part of the United States. Much greater changes came from the completion of the Santa Fe railroad line from Chicago to Los Angeles in 1885. Immigrants flooded in, especially white Protestants from the Midwest. Los Angeles had a strong economic base in farming, oil, tourism, real estate and movies. It grew rapidly with many suburban areas inside and outside the city limits.