The map shows the population of enslaved people in the United States in 1790. A map of Enslaved People in the United States in 1790.
As this map shows, the Virginia Plan would have

given Northern states greater control over the executive branch of the federal government due to the voting population.
given Southern states greater control in the legislative branch of the federal government due to representation.
weakened the federal government due to the disenfranchisement of the enslaved population.
weakened the federal government due to the lack of taxes paid by the enslaved population.