Which act limited U.S. citizenship to white individuals and those of African descent?

The Naturalization Act of 1870 is significant because it marked a change in U.S. immigration law regarding naturalization. Prior to this act, the only groups explicitly allowed to become U.S. citizens were free white individuals, as stipulated in earlier legislation. The 1870 Act expanded eligibility for naturalization to individuals of African descent, thus including Black individuals but still maintaining restrictions based on race. It reinforced the idea that citizenship was limited primarily to white individuals and those defined as being of African descent. This act signaled a step towards inclusivity for some, but it also highlighted the racial boundaries that were still firmly in place in American law during that period. The other acts mentioned, such as the Chinese Exclusion Act, were specifically aimed at restricting immigration from certain countries rather than directly shaping the parameters of citizenship in the same way.