Final answer:
At the Constitutional Convention, delegates faced friction primarily due to the representation issue between small and large states and the contentious issue of slavery. These debates laid the groundwork for future conflicts, notably reflected in the Lincoln-Douglas debates that foreshadowed the Civil War.
Step-by-step explanation:
Two important issues caused significant friction between the delegates during the formation of the United States Constitution. The first issue was the representation of small states versus large states in the new government structure, with large states favoring representation based on population and small states seeking equal representation.
This friction was evident as representatives from southern states worried about an abolitionist push from the northern states, leading to debates and intense scrutiny of how to address the issue within the Constitution. Moreover, the question of representation led to heated debates, resulting in the eventual creation of a bicameral legislature to balance the interests of states with different populations.