In 1781 twelve families trooped north from Mexico to
California. On a stream along the desert’s edge, they built a settlement called
Los Angeles. For many years it was a market town, where nearby farmers and
ranchers met to trade. Then in 1876 a railroad linked Los Angeles to San
Francisco and, through San Francisco, to the rest of the country. The next year
farmers sent their first trainload of oranges east. By 1885 a new railroad
provided a direct route between Los Angeles and Chicago. Then
in the 1890’s oil was discovered in the city. As derricks went up, workers built
many highways and pipe lines. Digging began on a harbor that would make Los
Angeles not only an ocean port but also a fishing center. The harbor was
completed in 1914. That year the Panama Canal opened. Suddenly Los Angeles was
the busiest port on the Pacific Coast. Today the city is the
main industrial center in the West. It produces goods not only for other West
Coast communities but also for those in other parts of the country. It leads the
nation in making airplanes and equipment for exploring outer space. Many motion
pictures and television programs are filmed in Los Angeles. The city is also the
business center for states in the West. Improvements in transportation are the
main reason for Los Angeles’ growth. According to the passage, what was the main commercial activity of Los
Angeles during the years directly following its settlement