That's it? No cites, no arguments, nothing?
Of the approximately 1400 cases which reached the Supreme Court under the (commerce -rp) clause prior to 1900, the overwhelming proportion stemmed from state legislation. The result was that, generally, the guiding lines in construction of the clause were initially laid down in the context of curbing state power rather than in that of its operation as a source of national power."
caselaw.lp.findlaw.com/data/constitution/article01/28.html
That's the reason the full power of the Commerce Clause wasn't used. It wasn't necessary.
"then why delegate such a power to Congress in the first place?"
Foresight?
"The US managed to get along for about 150 years without the New Deal "substantial effects" test."
You really need to familirize yourself with the Shrevepoert Rate Case (20 years before the New Deal "substantial effects" test) which dealt with intrastate commerce having an effect in interstate commerce. To wit:
"It is for Congress to supply the needed correction where the relation between intrastate and interstate rates presents the evil to be corrected, and this it may do completely, by reason of its control over the interstate carrier in all matters having such a close and substantial relation to interstate commerce that it is necessary or appropriate to exercise the control for the effective government of that commerce.
Your claim that there was very little interstate trade is flat out ridiculous.
There was a thriving interstate and foreign trade in rum, tobacco, agricultural products, guns, etc.
Obstacles to trade was one of the problems under the Articles of Confederation. That's why the power to regulate interstate trade was delegated to Congress.
What is the basis for saying there was very little interstate trade?
Of the approximately 1400 cases which reached the Supreme Court under the (commerce -rp) clause prior to 1900, the overwhelming proportion stemmed from state legislation. The result was that, generally, the guiding lines in construction of the clause were initially laid down in the context of curbing state power rather than in that of its operation as a source of national power." caselaw.lp.findlaw.com/data/constitution/article01/28.html
Correct, the Commerce Clause was used by the USSC to strike down State laws which interfered with interstate commerce.
Striking down a State law is different than Congress passing a Federal law governing intrastate activity.
That's the reason the full power of the Commerce Clause wasn't used. It wasn't necessary.
What made it necessary at the time of the New Deal and beyond?
"It is for Congress to supply the needed correction where the relation between intrastate and interstate rates presents the evil to be corrected, and this it may do completely, by reason of its control over the interstate carrier in all matters having such a close and substantial relation to interstate commerce that it is necessary or appropriate to exercise the control for the effective government of that commerce.
USSC was ruling on rail rates. The "evil to be corrected" was basically a tariff to interstate trade. It was not a green light for Congress to create a massive, intrusive Federal bureaucracy. That was the New Deal "substantial effects" test of which which you are so enamored.
As Clarence Thomas wrote in Lopez:
I am aware of no cases prior to the New Deal that characterized the power flowing from the Commerce Clause as sweepingly as does our substantial effects test. My review of the case law indicates that the substantial effects test is but an innovation of the 20th century.