Why is it called Harry potter and the sorcerers stone in America?

It is called this because when Harry goes to Gringgotts (wizard bank) Hagrid takes the sorcerers stone out and brings it to Hogwarts (wizard school). Harry and his friends find out everything they need to know to get to it. The more they find out about it, the more likely it seems it as someone is plotting to steal it. It just so happens that they were right. They go through many different rooms and finally leave Harry in the last room. He finds his defense against the dark arts teacher there sharing his body with Voldemort. (Voldemort is the one who killed Harry's parents and also tried to kill him!) He manages to escape him again and Dumbledore seeing that having the stone could bring harm to the students destroys it. So if finding the stone was the big idea why not call it that?