Los Angeles' modern history essentially begins with the Spanish colonization of California. In 1769 Spanish Franciscans reached the coast near LA and by 1771, Mission San Gabriel was constructed in what is now San Gabriel. Within a decade, the Spanish trail connected Los Angeles to Santa Fe, a major spanish center at the time. Due to the harshness and peril in crossing Arizona, the trail went north through Utah and Nevada. However, the trailed dipped south around the Sierra Nevadas, which places one quite close to the fledgling city.

Los Angeles slowly developed into a major farming community. The alluvial floodplains of the Los Angeles and San Gabriel rivers provided fertile soil for crops and animals. When the mining rushes hit Northern California in the mid 19th century, LA was well-positioned to take advantage of the demand. The city quickly became one of the largest producers of beef in the state.

However, LA's population was ready not to explode yet. LA was located close to the Mexican-American border during one of the most violent periods of American history. Banditos and outlaws preyed on residents and crime ran rampant. By the 1870s, this tide was changing. Investment started to flow into the city from outside and the commercial opportunities of LA came to light. Dredging in San Pedro bay and the Los Angeles - San Pedro railroad greatly improved the commercial importance of the region. Safer stagecoach lines from Yuma and Salt Lake City had made travel much easier, but Los Angeles truly exploded when the California Southern railroad connected it to the Santa Fe railroad. For the first time, travel from the population centers of the east became viable. At the same time, construction of the ports of Long Beach and Los Angeles opened the city to international trade. The importance of these facilities in the future of LA would not become clear until 1892, when oil was discovered in the Los Angeles basin.

By the 1920s, Los Angeles was producing a quarter of the world's oil. The film studies had set up shop in Hollywood, seeking refuge from the Edison on the East coast and taking advantage of the beautiful LA weather. The importance of Hollywood in the emergence of Los Angeles onto the world stage cannot be easily overstated. The constant appearances, enormous inflowing investments reinforced the city's meteoric rise into prominence. By the 1950s, the area had begun converting old farmland into tract housing to support its burgeoning population. Together with the ready access Los Angeles had to wider trade networks, a huge industrial and creative base formed in the city, further improving its stature. The momentum it built up in the early to mid 20th century provoked development, which in turn promoted further development. LA was locked in a self-reinforcing cycle of expansion that led the city to where it is today.