Isn’t that what our Constitution says we all get?
Actually, no.
The principle of “innocent until proven guilty” is not in the Constitution, Declaration of Independence, or any other founding document of the United States. It was an unwritten tenant of English Common Law.
The phrase entered US law through a 1894 Supreme Court decision, which reversed a lower court because the jury had not been instructed “The law presumes that persons charged with crime are innocent until they are proven by competent evidence to be guilty”.
"The enumeration in the Constitution, of certain rights, shall not be construed to deny or disparage others retained by the people."
During ratification, Amendment IX was well known to have referred to respect for the rights of Englishmen under the Common Law not already recognized in the 4th, 5th, and 6th Amendments. At that time, presumptive innocence would only have applied to Federal crimes, but would have been understood in the Constitutions of most states.
Coffin v. United States, did not really establish the principle of presumptive innocence -- in fact the decision itself goes through the whole body of existing case law in which this was already understood.
What Coffin did do is establish that failure to advise a jury of presumptive innocence was so serious that it was, in itself, a reversible error.