The Framers of the Constitution agreed on many things. Clearly, they had to agree with everything that is in the Constitution. Let us look at their most important points of agreement.
First, they agreed that the United States needed to be democratic. They agreed that the people had to be able to elect the House of Representatives and indirectly, the Senate and the President. They agreed that the states had to have democratic forms of government.
Second, they agreed that the US should not be too democratic. They did not want the people to have too much control over the government. That is why they did not allow the people to directly elect the Senate or the President. It is also why they did not allow the people to elect the Supreme Court at all.
Third, they agreed that there should be separation of powers and checks and balances. They agreed that it would be bad if one branch of government had all the power because that branch would then be able to easily violate the rights of the people. They also agreed that there had to be checks and balances so that each branch could stop the other branches if it thought the other branches were doing things that were bad.
Finally, they agreed that the US should have a federal system. This meant that the national government had to have some powers while the state governments had to have other powers. They did not want a system in which one level of the government dominated.
These are the most important things on which the Framers agreed.