primaries, ensuring minorities were excluded from the formal political process. The number of voters dropped dramatically, and the Democrats crushed competition from the Republican and Populist parties. The Socialist Party became the second-largest party in Texas after 1912, coinciding with a large socialist upsurge in the United States during fierce battles in the labor movement and the popularity of national heroes like Eugene V. Debs. The socialists' popularity soon waned after their vilification by the United States government for their opposition to U.S. involvement in World War I. The Great Depression and the Dust Bowl dealt a double blow to the state's economy, which had significantly improved since the Civil War. Migrants abandoned the worst-hit sections of Texas during the Dust Bowl years. Especially from this period on, blacks left Texas in the Great Migration to get work in the Northern United States or California and to escape the oppression of segregation. In 1940, Texas was 74% Anglo, 14.4% black, and 11.5% Hispanic. World War II had a dramatic impact on Texas, as federal money poured in to build military bases, munitions factories, POW detention camps and Army hospitals; 750,000 Texans left for service; the cities exploded with new industry; the colleges took on new roles; and hundreds of thousands of poor farmers left the fields for much better-paying war jobs, never to return to agriculture. Texas manufactured 3.1 percent of total United States military armaments produced during World War II, ranking eleventh among the 48 states. Texas modernized and expanded its system of higher education through the 1960s. The state created a comprehensive plan for higher education, funded in large part by oil revenues, and a central state apparatus designed to manage state institutions more efficiently. These changes helped Texas universities receive federal research funds. Mid-20th to early 21st century Beginning around the mid-20th century, Texas began to transform from a rural and agricultural state to one urban and industrialized. The state's population grew quickly during this period, with large levels of migration from outside the state. As a part of the Sun Belt, Texas experienced strong economic growth, particularly during the 1970s and early 1980s. Texas's economy diversified, lessening its reliance on the petroleum industry. By 1990, Hispanics and Latino Americans overtook blacks to become the largest traditional minority group in the state. Texas has the largest Black and African American population with over 3.9 million. During the