1Jared Sparks: Notes on conversations with James Madison, 19 April 1830 (Madison Papers)
The apportionment of taxation in the old states of 3/5 for slaves was decided rather from accident, than any accurate calculation. The subject caused much debate in Congress. The east and the south differed. The former was for a high ratio, the latter for a low;—¼, ½, 2/3 were proposed and rejected. At length Mr Madison proposed 3/5, which was accepted, & he still thinks it very near the true...