www.dol.gov/elaws/faq/esa/flsa/003.htm
From what I found out the Feds in the US say Min wage must be paid to anyone under 20 after 90 days. Unless disabled or the job is like onsite training for the students degree/diploma
Which president made it so the minimum wage doesn't apply to people under 18?
I'm not sure … but if you find when that was passed, you can figure out which President signed it. Of course, it would be CONGRESS that passed the legislation for the President to sign.