Complex sentence: He was brought to Los Angeles at the age of 15 in 1884 or 1885 and graduated from Los Angeles High School in 1889, after which he read law in the office of Houghton, Silent & Campbell.
Split into simpler sentences: He was brought to Los Angeles at the age of 15 in 1884 or 1885 and graduated from Los Angeles High School in 1889. He read law in the office of Houghton, Silent & Campbell.