At the Constitutional Convention, the Delegates vote (YEA, 7; NAY, 3; ABSTAIN, 2) to ban import duties between States, thus making the voluntary Union one great free trade zone.
[added 11/29/2024]
Subsequent Events:
Authority:
Articles of Confederation, Article XIII
ccc-2point0.com/Articles-of-Confederation
References:
Avalon Project – Madison Debates – September 13
avalon.law.yale.edu/18th_century/debates_913.asp