Apparently there’s no federal law (in the US) banning the ownership of human bones because up until the mid to late 20th century it was apparently common practice for med students to purchase real human bones for their studies. Most of them apparently came from India, until the country banned the export of human remains, which must have played a part in causing the practice to fall out of style.
If anyone has anything to correct/add, please do so. This was just a quick google search out of morbid curiosity