254) was a United States federal law that created a system of controls for the naturalization process and penalties for fraudulent practices.

It is also noted for extending the naturalization process to "aliens of African nativity and to persons of African descent" while also maintaining exclusion of the process to Chinese Americans and other groups.

[3] By virtue of the Fourteenth Amendment and despite the 1870 Act, the US Supreme Court in United States v. Wong Kim Ark (1898) recognized US birthright citizenship of an American-born child of Chinese parents who had a permanent domicile and residence in the United States, and who were there carrying on business, and were not employed in any diplomatic or official capacity under the Emperor of China.

[4] US citizenship of persons born in the United States since Wong Kim Ark have been recognized, although the Supreme Court has never directly made a ruling in relation to children born to parents who are not legal residents in the United States.

The 1870 Act was passed by the 41st US Congress and signed into law by President Ulysses S. Grant on July 14, 1870.