Final answer:
The 'Great Compromise' solved the major issue of how each state would be represented in Congress.
Step-by-step explanation:
The major issue of the Constitutional Convention that was solved by the 'Great Compromise' was how each state would be represented in Congress. The 'Great Compromise', also known as the Connecticut Compromise, proposed a bicameral congress with two chambers - the Senate and the House of Representatives. In the Senate, each state would have equal representation with two senators, while in the House, representation would be based on the population of each state.