March 31, 1870, the morning after the 15th Amendment became law, Thomas Mundy Peterson (1824-1904) entered a polling place in Perth Amboy, New Jersey, and cast a ballot, the first Black American to vote under its authority, while the nation barely noticed. In this unremarkable setting an ordinary act of governance, a single vote in a small city, federal citizenship met local power and the meaning of political inclusion was tested in practice rather than proclaimed in theory.