Book excerpt: Railroads have been a part of Orange County for over 130 years. The great names of American railroading--Atchison, Topeka, and Santa Fe; Southern Pacific; and Union Pacific--were firmly planted here by the early 1920s and linked with the largest interurban rail system in the United States, the famed Pacific Electric Railway. Thousands of people passed through Orange County's depots during the 1940s as they came to serve at the many military bases located here during World War II. The names have since changed, and yet the county's rail scene remains as dynamic as ever, with Amtrak, Metrolink, and amusement park railroads joining the Burlington Northern Santa Fe and Union Pacific. Railroad depots, new and old, are located across Orange County and continue on both as vital parts of history and the future of transportation for America's fifth most populated county.