The plan introduced at the Constitutional Convention that provided for a federal government that would be a combination of the states and a national government was known as the

The three branches of government

Explanation:

Introduced to the Constitutional Convention in 1787, James Madison's Virginia Plan outlined a strong national government with three branches: legislative, executive, and judicial.

the virginia plan

Explanation: In 1787 at the constitutional convention james madison made a plan for the virginia plan to come into play including the form a strong national goverment with three branches of power that are evenly in power.

The plan called for a legislature divided into two bodies (the Senate and the House of Representatives) with proportional representation.

i just did something on this guy a few days a go give me two minutes to find it in my notes.