The entry of the Chinese into the United States was, to begin with, legal and uncomplicated and even had a formal judicial basis in 1868 with the signing of the Burlingame Treaty between the United States and China. But there were differences compared with the policy for European immigrants, in that if the Chinese migrants had children born in the United States, those children would automatically acquire American citizenship. However, the immigrants themselves would legally remain as foreigners "indefinitely". Unlike European immigrants, the possibility of naturalization was withheld from the Chinese.