What???
Where did the Founders ever say that? That has got to be one the most ridiculous things I've ever read on FR -- and that's saying something.
"Can you back it up with examples demonstrating where I have done this?"
Refer to my previous statement.
What's ridiculous about it? It quite true, and perfectly reasonable. The national government can make trade "regular" between the states by preventing them from imposing artificial trade barriers, and in fact this is the only use of the commerce power for regulating interstate commerce I can find any reference to by any of the Founders.
Congress cannot prevent foreign nations from imposing artificial trade barriers, they can only answer whatever barriers are erected in kind.