| California County Formation years | ||||||||||||||
| 1850 | 1851 | 1852 | 1853 | 1854 | 1855 | 1856 | 1857 | 1859 | 1860 | 1861 | 1863 | 1864 | 1866 | 1868 |
| 1870 | 1872 | 1874 | 1875 | 1876 | 1878 | 1881 | 1885 | 1887 | 1889 | 1891 | 1893 | 1897 | 1907 | 1909 |
| 1913 | 1917 | 1919 | 1925 | |||||||||||
| California County Census Year with Modern Map overlayed: | ||||||||||||||
| 1850 | 1860 | 1870 | 1880 | 1890 | 1900 | 1910 | 1920 | 1930 | ||||||
| California Census Year with previous Census Year overlayed: | ||||||||||||||
| 1860 | 1870 | 1880 | 1890 | 1900 | 1910 | 1920 | 1930 | |||||||
| California Census Year with Modern Map overlayed: | ||||||||||||||
| 1850 | 1860 | 1870 | 1880 | 1890 | 1900 | 1910 | 1920 | |||||||
| California Map Abbreviations | ||||
|---|---|---|---|---|
|
unorg. = unorganized g. = gained w. = with fr. = from atmt. = attachment exch = exchanged nca.= non county area ch. = changed Ala - Alameda Alp - Alpine Am - Amador But - Butte Ca - Calaveras |
CC - Contra Costa Col - Colusa Cos - Coso Csi - Colusa DN - Del Norte ED - El Dorado Fr - Fresno Gl - Glenn Hu - Humboldt Im - Imperial In - Inyo Ke - Kern Ki - Kings Kl - Klamath |
LA - Los Angeles Lak - Lake Las - Lassen Mad - Madera Men - Mendocino Mer - Merced Mno - Mono Mnt - Monterey Mod - Modoc Mrn - Marin Mrs - Mariposa Na - Napa Ne - Nevada Or - Orange |
Pa - Pautah Pla - Placer Plu - Plumas Ri - Riverside Sac - Sacramento SBr - San Bernardino SBt - San Benito SCl - Santa Clara Scr - Santa Cruz SD - San Diego SF - San Francisco Sh - Shasta Sie - Sierra Sis - Siskiyou |
SJ - San Joaquin SLO - San Luis Obispo SM - San Mateo Sol - Solano Son - Sonoma St - Stanislaus StB - Santa Barbara Su - Sutter Te - Tehama Tr - Trinity Tul - Tulare Tuo - Tuolomne Ve - Ventura Yo - Yolo Yu - Yuba |