The "Cornerstones of Freedom" detail important events in United States history. Children are given the sense of being witnesses to history-in-the-making and contemporaries of famous people who helped shape the United States into the world power it is today. Starting with the Spring 1992 titles, a brand-new format has been introduced using more photographs (many in full-color), historical engravings, and an easy-to-read typeface. Many popular previously published titles will be updated in this new format. Each book includes an index