Passed by the California legislature in 1913, the Alien Land Act prohibited noncitizens from owning land in California. Californians had for 20 years been campaigning against Chinese and Japanese immigrants, who they feared were overrunning their state and threatening their traditional culture. An increasing number of Indian immigrants after the turn of the century (see Indian immigration) led to a variety of discriminatory measures, including the Alien Land Act. The measure was challenged by Takao Ozawa, who first immigrated to the United States from Japan in 1894, but the U.S. Supreme Court ruled in Ozawa v. United States that by race he was excluded from U.S. citizenship.