In the early 1900s, Texans became involved in the Mexican Revolution and World War I. During the Mexican Revolution, rebel leader Francisco (Pancho) Villa had his base across the Rio Grande from El Paso. After he raided New Mexico, 6,000 troops from San Antonio were sent to Mexico to find him.

World War I Almost 200,000 Texans served in the Army, Navy, and Marine Corps during World War I. About one-fourth of the Texans who served were African Americans, and hundreds of Mexican Americans served as combat troops. The army established training camps at Houston, Fort Worth, Waco, and San Antonio. Camp Kelly in San Antonio became the largest flight training school in the world. On the home front, Texans supported the Liberty Loan campaigns and voluntarily rationed their food.

After the War Soldiers were greatly changed by the war. They experienced training, education, and new cultures. After the war, they returned to a Texas that also had changed. The state had prospered because Texas produced so many things the military needed, such as cotton, wool, leather, meat, and petroleum. The urban population had grown by 58 percent, and many houses had electricity. The Texas highway system and the radio and motion picture industries had grown. Women now had the right to vote.

So much rapid social change occurred that some people began to resist change. The most visible reaction was the growth of the Ku Klux Klan, a secret organization that terrorized African Americans, Jews, Catholics, and others. The Klan also engaged in politics, putting Klan members in government. Yet in 1924, Miriam "Ma" Ferguson became governor on an anti-Klan platform. Another woman, Annie Webb Blanton, was very influential in improving Texas education.