Answer:
Missouri Comp.
Explanation:
Scott v. Sandford declared that the Missouri Compromise was unconstitutional meaning that congress had no power over slavery
What was common is that they were both fought as plans of Lee to move the fighting no Northern Parts of the federation. Antietam ended in a draw, while Gettysburg became a victory for the Union.
It's a close run between all of the above and C. If I would have to choose, I'd say C, since executing ALL the Spanish seems a bit extreme.<span />