Describes scenes along the Mississippi River over the course of a week, beginning in Minnesota when it is a tiny stream and going all the way to the gulf coast of Louisiana. Includes a section of historical information about the river.

In 1860, eleven-year-old Becky Thatcher, new to St. Petersburg, Missouri, joins the boys at school in a bet to steal from the Widow Douglas in hopes of fulfilling a promise to have adventures that she made her brother Jon before he died.