The number of enslaved people counted towards Virginia's population in 1798 depends on the application of the Three-Fifths Compromise, which stipulated that each enslaved person was counted as three-fifths of a person for purposes of representation and population counts. If there were 500,000 enslaved people in Virginia in 1798, then the number of enslaved people counted towards its population would be three-fifths of 500,000, which is:
35×500,000=300,000\frac{3}{5}\times 500,000=300,00053×500,000=300,000
Thus, 300,000 enslaved people would be counted towards Virginia's population under the Three-Fifths Compromise.
In historical context, the total population of Virginia in the 1790 census was about 747,610, with a significant portion being enslaved people (292,627 slaves according to the 1790 census). The Three-Fifths Compromise was used for congressional representation and population calculation during this time period.