Laura Ingalls Wilder is legendary. Her "Little House on the Prairie" series, based on her family's adventures on the Midwestern frontier, have sold more than 41 million copies in the U.S. and have been translated into more than 40 languages. The books spawned a long-running television show and, in 2008, a stage musical. Millions of readers have been captivated by Wilder's childhood on the prairie, but her newest book, "Pioneer Girl," released more than 50 years after her death, offers a new perspective. Annotated with exceptional detail by Pamela Smith Hill, "Pioneer Girl" is Wilder's autobiography, unpublished until now. Hill's...