How many copies of Harry Potter and the Chamber of Secrets were sold on the first day of publishing in the US?

On its release day in the United States on June 2, 1999, "Harry Potter and the Chamber of Secrets" sold approximately 2 million copies. This impressive figure contributed to the series' rapid rise in popularity and solidified J.K. Rowling's status as a leading author in children's literature. The book's success was part of the larger phenomenon surrounding the Harry Potter series.