Lancaster is the fifth-largest city in Los Angeles County, California, and the ninth-fastest growing city in the United States. Lancaster is the 30th largest city in California, and the 148th largest city in the United States. Lancaster is the principal city within the Antelope Valley. Lancaster is located approximately 70 miles (110 km) north (by road travel) of the city of Los Angeles in Southern California's Antelope Valley. It is separated from the Los Angeles Basin by the San Gabriel Mountain Range to the south and from Bakersfield and the San Joaquin Valley by the Tehachapi Mountain Range to the north. The population of Lancaster has grown from 37,000 residents at the time of incorporation in 1977, to 156,633 people as of the 2010 census, which makes it the largest city on the California side of the Mojave Desert.
Lancaster was the first community settled in the Antelope Valley, although Palmdale ended up incorporating as a city slightly sooner. The community of Lancaster was settled in the late 19th century by M.L. Wicks, a real estate developer who purchased six sections of land from the Southern Pacific Railroad (now merged into the Union Pacific Railroad). The origin of the city's name is uncertain, but it is presumed to be named after Lancaster, Pennsylvania, or, more likely, the original Lancaster in Lancashire, England.
Early in its history, Lancaster was little more than a whistle-stop on the Southern Pacific Railroad between San Francisco and Los Angeles, with one hotel, the Gilwyn (known today as the Western Hotel), and a handful of homes. The settlement grew quickly, however, and by 1890, Lancaster was quite prosperous. The town experienced another small boom at the turn of the 20th century when gold and borax were discovered simultaneously in the mountains around the Antelope Valley. With the advent of the aerospace industry came the groundwork for the modern city growth. In 1933 the United States Army Air Corps began conducting flight and weapons tests at Muroc Army Air Field (now Edwards Air Force Base) and Lancaster has grown steadily since that time. It is home to many employees of Edwards Air Force Base, as well as to employees of Boeing, Lockheed, and Northrop Grumman, all of which have manufacturing facilities at U.S. Air Force Plant 42 which is south of the Lancaster city limits.