Three-fifths (slaves): An 8-page newspaper, The Balance and Columbian Repository, Hudson NY -- Tuesday July 2, 1805. Published by Harry Croswell, Warren-Street, Hudson. There is an interesting 2-page anti-slavery article in relation to the US Constitution and citing slave population statistics in the southern/northern states written by Mr. James Elliot, who was a Representative from Vermont. You may have heard of slaves being referred to as three-fifths of a human being. This article is the first mention I have seen presenting the concept of the numbers and ratios of representatives (Congress and Senate) from the northern states and slave-holding southern states. Elliot makes the case for slaves being represented as three-fifths in the United States so that the number of votes for anti-slavery legislation in the northern states would be more -- hopefully defeating the slave trade. This is a political perspective, with the desire to fight the practice of slavery in America. The South was counting slaves as a part of their number of constituents, hence a greater number of pro-slavery votes. The Northern states didn't have near the same number of slaves, so there was less representation in Congress and the Senate. Take a look at a transcription of the full article here.
-- Background: The three-fifths ratio was not a new concept. It originated with a 1783 amendment proposed to the Articles of the Confederation. The amendment was to have changed the basis for determining the wealth of each state, and hence its tax obligations, from real estate to population, as a measure of ability to produce wealth. (It started out as a way of increasing taxes and then later reversed as a way to counter the representation in government. The above-mentioned article reveals the latter view.)