It was the first ( and only ) such federal tax .
To pay for it , Congress in July 1798 imposed $2 million in new taxes on real estate and slaves , apportioned among the states according to the requirements of the Constitution .
Congress was the first ( and only ) such federal tax .
To pay for it , Congress in July 1798 imposed $2 million in new taxes on real estate and slaves , apportioned among the states according to the requirements of the Constitution .