Stores including Hastings and Barnes and Noble hosted parties for the droves of sorcerers, magic users and muggles.
Kayla Cristy was equipped in full Harry Potter attire and armed with a magic wand.
"It's actually very sad it's the last book," said Cristy. "But at the same time, I'm excited to know everything."
Some are calling this event a part of publishing history.
"We'll never see this again," said Barnes and Noble manager Wade Watlley. "You'll never see this many volumes sold at one time."
Sales are estimated to reach the tens of millions worldwide.
As the fans participated in costume contests and enjoyed various Harry Potter themed food, everyone knew that once the clock chimed midnight they would finally hold in their hands the final pages of the Harry Potter quest.
"It's deffinetly going to be hard to say goodbye to him in the books," said Cristy. "I'm probably going to cry after I'm done reading the book, but I think I'll always have Harry Potter with me forever."