Answer:
By convincing the leaders that having a strong central government will be beneficial for their states.
Step-by-step explanation:
The earlier draft of United States constitution were made by the founding fathers who at that time did not have much experience in running a government.
Because of this, the initial draft created a lot of weaknesses for the central government, making it impossible for the central government to fully control the actions made by each states. This caused a lot of problems for the federal government.
So, Madison made a list of argument during a convention that having a stronger central government will be beneficial for the states. For example, it could help the federal government mobilize the military's more efficiently if the states need some helps. On top of that, it also allow the federal government to act as a mediator in case the smaller states engaged in a conflict. This led to the ratification of the initial draft of the constitution.