How did augustus change the roman republic

Augustus changed the republic by adding another layer of political office, namely that of the "first citizen" to the magistrates. Although the consuls were still in office, they had little or no power as the main powers and authorities rested in the first citizen, a.k.a. emperor.

the united states has a federal government. the president is the head of the federal government of the united states. however, each state forms its government for administration purposes. the powers of the state governments are exercised within restricted state boundaries. and citizens participate in this government by voting.