The 1879 constitutional convention also dispatched a message to Congress pleading for strong immigration restrictions, which led to the passage of the Chinese Exclusion Act in 1882. The act was upheld by the U.S. Supreme Court in 1889, and it would not be repealed by Congress until 1943. Similar sentiments led to the development of the Gentlemen's Agreement with Japan, by which Japan voluntarily agreed to restrict emigration to the United States. California also passed an Alien Land Act which barred aliens, especially Asians, from holding title to land. Because it was difficult for people born in Asia to obtain U.S. citizenship until the 1960s, land ownership titles were held by their American-born children, who were full citizens. The law was overturned by the California Supreme Court as unconstitutional in 1952.