Cornerstones of Freedom, Second Series, is the updated and newly designed extension of the acclaimed original series. Focusing specifically on key events in American history, from colonial times to the present day, the Cornerstones books support history, social studies, and geography curricula for middle-school students. Each book includes expanded subject coverage, subheadings, informative sidebars, glossary terms, timelines, and additional resources, as well as an attractive new design and dramatic photographs. In the 1800s, more than 100,000 slaves successfully escaped to freedom on the Underground Railroad. This in-depth look at the Underground Railroad includes information on how this secret network developed and how it operated. Also included are profiles of the major players involved in the Underground Railroad: Harriet Tubman, Levi Coffin, and Calvin Fairbanks.