how did chiropractic become legal in the US?!
Question: How did chiropractic become legal in the US?
Answers:
Chiropractic began in the US in 1898. The profession was born and the first school established at a time when there was less oversight buy govt agencies. The medical profession for a time claimed that chiros were practicing medicine without license and many people went to jail for this. This made practice very hard. As a result the profession had to go through some legal challenges to separate itself from the medical community. That is where chiro began the path toward back pain doctors. It allowed a distinction to the medical community and the public and people stopped going to jail.
Atlarge is right, as far as I can see.
While there has always been controversy within the medical community concerning chiropractics, I could find nothing that indicated it was EVER illegal, just not well received.
It didn't 'become' legal because it was never illegal.