Oh baloney. You're just repeating what you've heard. Do some research for yourself, for once.
Congress was regulating commerce within the states as early as 1914, 20 years before FDR. I can provide you with a link to the Shreveport Rate Cases if you wish.
We've been there and done that, RP. The Shreveport case was about Congress preventing what amounted to an unfair tariff on interstated commerce by manipulating the rail rates. They were regulating the railroads as "instruments of interstate commerce", not the commerce itself. Your assertion that Wickard doesn't cover any ground that Shreveport didn't doesn't hold up.
Every time I start doing my own research, and find out what the founders had to say about the Commerce Clause, and "commerce among the several states", I find more and more evidence that you're wrong. Are you sure you want me doing any more?