Federalism because Amendments are proposed at a federal level and is ratified at a state level. Why have only 27 Amendments been added to the Constitution? Because of Informal Amendments and how easy it is to informally amend it rather than formally.
There were two plans suggested for the representation in Congress.
One was the Virginia Plan, and the other was the New Jersey plan. The Virginia plan suggested that the states should get representation based on their population, and the New Jersey plan suggested the states would get equal representation.
Smaller states of course would favor the New Jersey plan, because they didn't want to lose power in Congress.
They ended up compromising on this. They made the House of Representatives, which used the Virginia plan, and the Senate, which used the New Jersey plan. (The Senate has more power than the House of Reps)
C. Success of growing wheat in the hillsides
The Great Awakening, because it was a religious revival that encouraged people to go back to church and join a religion.