Further assuming you want to irritate your Liberal Professor and classmates, there's nothing like shoving the fact down their throats that it was DEMOCRATS who fought the 14h Amendment's passage because as citizens the newly freed slaves wold have the right to bear arms. And that they (the DEMOCRATS) specifically feared bands of ARMED BLACKS roaming the countryside raping white woman as gun point. And that most Southern states, controlled by DEMOCRATS, refused to ratify the Fourteenth Amendment because of this.
And that it was REPUBLICANS in Congress who then had to FORCE said Southern DEMOCRATS into 'giving' BLACKS their rights by the 1867 Reconstruction Acts, and said states where then controlled by martial law, which proclaimed universal manhood suffrage and required that new state constitutions to be drawn up.
Again, it ain't 20th century but it's where the first fight over Civil Rights & 2nd Amendment Rights arose - plus it'll tick off the liberals when you throw it in their face.
of course they won't like to hear any mention of the oldest civil rights organization in America...the NRA.