It would be "Whether a new state or territory should enter the Union as Free or Slave" that had the most impact on the Civil War, since the North was strongly against the spread of slavery, while the South was in favor of it.
Number 9 Is: 156 And 10 Is: 15 Hours, 900 Minutes
Answer:
The larger a population is in a state, the more representatives you will have from the House of Representative. The amount of represenatives from the Senate is fixed at 2 per state.