Hmm...Citizenship is defined in the Constitution itself - Article I, Section 8, Clause 4 gives congress the power to determine citizenship. The Constitution does say that anyone living in the United States upon ratification is a US citizen. Also note that citizenship for Black Americans is solidified in the Fourteenth Amendment, which overturned the Dred Scott v. Sandford decision.
It was the 14th Amendment that gave African Americans full citizenship
The 13th Amendment
14th amendment
The 14th Amendment to the US Constitution was the first to address citizenship. This amendment defines citizenship. It also contains the Privileges or Immunities Clause, the Due Process Clause and the Equal Protection Clause.
The 13th Amendment
Fourteenth Amendment
Amendment 14 confers citizenship on all such people.
suffrage amendment
it expanded the definition of citizenship to include voting rights for younger adults
The thirteenth amendment
The fourteenth amendment addresses citizenship. Initially it was in relation to the subject of slaves and their citizenship, but it has crossed over to citizenship in general.
nationalizing it and giving it constitutional protection