Historically, California's population was centered in the northern half of the state, but it has steadily moved southward, according to the U.S. Census Bureau. It is now in Shafter, a city just outside Bakersfield.
In its 2010 Guide to State and Local Census Geography, the bureau plots the state's population center from 1880 through the 2010 census.
"The center is determined as the place where an imaginary, flat, weightless and rigid map of the United States would balance perfectly if all residents were of identical weight," according to the bureau.
In 1880, the state's center was just west of Stockton, but by 1910, it fell west of Fresno. Twenty years later, it moved closer to Bakersfield, and the middle of the state's population has roughly stayed in that area ever since.
In addition to plotting the historic center of each state's population, the guide presents facts on several aspects of state geography. For instance, California's entry tracks "108 federally recognized American Indian areas," with 104 classified as reservations and the remaining four as land trusts or tribal statistical areas.
Not surprisingly, communities in and around Los Angeles County dominate the list of biggest and most populous areas in California.
The guide covers the 50 states plus the District of Columbia and promises information soon on the U.S. island areas of American Samoa, Guam, the Northern Mariana Islands and the U.S. Virgin Islands.
Historic centers of population for California, U.S. Census Bureau
California population, 1880-2010