The Virginia Plan was a proposal to establish a bicameral legislature—a legislature with two houses—in the newly-founded United States. The plan recommended that each state should be represented in the new legislature, the US Congress, on the basis of their population size. It also called for the creation of three branches of government: a legislature, an executive, and a judiciary.
The main advantage of the Virginia Plan was that it enshrined the important principle of checks and balances in the American system of government. With the government divided up into three distinct branches, it was felt that no one branch would be able to exert too much power. Each branch would act as a constraint on the other two. This was an important principle to the Founding Fathers, as they wanted to get as far away as possible from what they saw as the unrestrained tyranny of British colonial rule.
A further advantage of the plan was that it gave Congress the power to veto and override state laws. This proposal, the so-called federal negative, as it became known, was a way to ensure that the federal government under the new system would be strong and stable and wouldn't have to be involved in endless disputes with the states over the potentially vexed question of sovereignty.