There are 22 books in the American Girl History Mysteries series.
The American Girl History Mysteries series does not have a new book coming out soon. The latest book, Betrayal at Cross Creek (Book 22), was published in March 2004.
The first book in the American Girl History Mysteries series, The Smuggler's Treasure, was published in September 1999.
The American Girl History Mysteries series primarily falls into the Historical Mystery genre. This middle grade series was written for ages 8-12, but can be enjoyed by older readers as well.