Geographic Origins of Texas Inhabitants, 1850-2000
Geographic Origins chart
long description of chart

Texas-born Texans--those born and living in the state at each Census--have made up the biggest share of the state's population since 1850, if we count the state's pre-Civil War slave population. The proportion of Texas-born residents rose to a peak of almost 79 percent of the total population in 1940, but has fallen steadily since then. In-migration from other states and countries continues to swell the number of Texans born outside the state.
Source: U.S. Census. (full source)