this is what I got from Google-
When the U.S. Supreme Court ruled in the Dred Scott decision that the Missouri Compromise's prohibition of slavery in territories was unconstitutional, an increasingly diverse body of opponents of slavery rallied around the Republican Party.
B. Lincoln had not dealt sternly enough with the southerners.
The correct answer is A. Both the Songhai and Mongol empires poured themselves into their military hierarchy to control the conquered regions.
Answer:
The end of the space race & the colapse of the soviet union
