The Marshall Court is considered to be central to the nation's history because it was one of the earliest courts to exist in the new nation--meaning many precedents were set. Perhaps the most long-lasting precedent set by this court in terms of impact was the precedent of judicial review--meaning that the court had the right to deem laws unconstitutional.
Slavery was incredibly divisive because the Us was expanding into the west, and each new state had to decide whether it was going to be "slave" or "free", so there was no middle ground in terms of how the extension of slavery would unfold. This led to the Civil War.
