Final answer:
The existence of slavery and the status of former slaves complicated the question of citizenship in post-revolution America. The Constitution did not initially define citizenship, and the 1790 Naturalization Act restricted citizenship to 'free White persons.' The Fourteenth Amendment in 1868 eventually established a federal definition of citizenship, granting it to all persons born or naturalized in the U.S., and promising equal protection under the law.
Step-by-step explanation:
The fact that complicated the question of citizenship in post-revolution America was D) The existence of slavery and the status of former slaves. The Constitution, when originally drafted in 1787, did not provide a clear definition of national citizenship, leaving it up to states to decide eligibility criteria. Over time, the concept of citizenship was limited by racial terms, specifically with the 1790 Naturalization Act that allowed only "free White persons" of "good character" to be citizens, excluding enslaved people, free Black people, Native Americans, and Asians from citizenship.
It was not until the ratification of the Fourteenth Amendment in 1868 that a federal definition of citizenship was established, stating that "All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside." This amendment was a monumental shift as it extended citizenship to all people born or naturalized in the U.S., regardless of race, and provided equal protection under the law.
However, the struggle for equal rights continued well into the 20th century, with Native Americans not receiving citizenship until 1924, and other legal and social barriers persisting against non-white citizens, underscoring the complexities and challenges in defining American citizenship in the post-revolution era.