The phrase 'one of the great revolutions of modern history' refers to:

• A. Civil rights and governance changes.
• B. Economic deregulation
• C. Foreign policy reform
• D. Territorial annexation

Answer: (A)

This phrase highlights the sweeping civil rights and governance changes that followed the Civil War. Reconstruction fundamentally redefined who could be a citizen and how the government protects those rights. The era produced the constitutional amendments that reshaped citizenship and voting: ending slavery, establishing equal protection under the law, and extending suffrage to Black men. It also created federal mechanisms to enforce those rights and reshape Southern governance, such as the Freedmen’s Bureau and Reconstruction Acts that placed federal authority over formerly Confederate states and reorganized political power there. These shifts in rights, citizenship, and federal–state relations mark the most defining changes of the period, rather than shifts in economics, foreign policy, or territorial borders.