James Madison, the Father of the Constitution, elaborated upon this limitation in a letter to James Robertson: With respect to the two words "general welfare," I have always regarded them as qualified by the detail of powers connected with them. To take them in a literal and unlimited sense would be a metamorphosis of the Constitution into a character which there is a host of proofs was not contemplated by its creators. If the words obtained so readily a place in the "Articles of Confederation," and received so little notice in their admission into the present Constitution, and retained for so long a time a silent place in both, the fairest explanation is, that the words, in the alternative of meaning nothing or meaning everything, had the former meaning taken for granted.
"Congress has not unlimited powers to provide for the general welfare but only those specifically enumerated." -- Thomas Jefferson