During the eighteenth and nineteenth centuries, the U.S. government took Indian lands, isolated Native Americans on reservations, and denied them political and social rights. The national government switched policies at the beginning of the twentieth century, promoting assimilation instead of separation. The government banned the use of native languages and religious rituals; it sent Indian children to boarding schools and gave them non-Indian names. In 1924, Indians received U.S. citizenship. Anger bred of poverty, unemployment, and frustration with an uncaring government exploded in militant action in late 1969, when several American Indians seized Alcatraz Island, an abandoned island in San Francisco Bay. The group cited an 1868 Sioux treaty that entitled them to unused federal lands; they remained on the island for a year and a half. In 1946, Congress enacted legislation establishing an Indian claims commission to compensate Native Americans for land that had been taken from them. Some of the 565 recognized tribes have successfully instituted casino gambling on their reservations. Many Mexicans became farm workers; others settled mainly in crowded, low-rent, inner-city districts in the Southwest, forming their own barrios, or neighborhoods, within the cities, where they maintained the customs and values of their homeland. World War II gave rise to another influx of Mexicans, who this time were primarily courted to work farms in California. In 1965, Cesar Chavez led a strike of the United Farm Workers union against growers in California. The strike lasted several years and eventually, in combination with a national boycott, resulted in somewhat better pay, working conditions, and housing for farm workers. The Census Bureau estimates that by 2050, one-third of all residents will be Hispanic. With such growth will come greater political power. After more than two decades of struggle, 43 million Americans with disabilities gained recognition in 1990 as a protected minority with the enactment of the Americans with Disabilities Act (ADA). The law extends the protections embodied in the Civil Rights Act of 1964 to people with physical or mental disabilities, including people with AIDS, alcoholism, and drug addiction. It guarantees them access to employment, transportation, public accommodations, and communication services. The roots of the disabled rights movement stem from the period after World War II. Thousands of disabled veterans returned to a country and a society that were insensitive to their needs. Congress moved a step closer in 2008, passing a revision to the ADA. The legislation increased protections for people with disabilities by making it easier for workers to prove discrimination. The ADA Amendments Act of 2008 gives protection to people with epilepsy, diabetes, cancer, cerebral palsy, multiple sclerosis, and other ailments. Federal court decisions had denied protection under the ADA because the disabling conditions were controlled by medication or were in remission. The bill was signed into law on September 25, 2008. Gays can now marry.