The transformation of American constitutional and legal history over the past few decades has been remarkable. What was once little more than an examination of the "great cases" has now expanded to include the economic, social, and political as well as the legal circumstances surrounding those controversies. Although great constitutional scholars such as E. S. Corwin and J. Willard Hurst had always understood the interconnection between law and history, in far too many universities a wide and often uncrossed street separated history and government departments from law schools. Today, more and more law schools are offering courses in legal and constitutional history and hiring non-lawyers who can bring the insights of other disciplines to bear on the law. Historians, on the other hand, are demonstrating that they can explicate the legal rulings in a case and place them in a developmental context.
The first edition of A March of Liberty attempted to blend the so-called new legal history with the usual emphasis on great cases. Large sections were devoted to topics that did not appear in the traditional constitutional history texts: common law developments, the relationship of commercial growth to legal change, the rise of the legal profession, changes in legal education, and the handling of certain key issues at the state level. These section grew out of a belief that the Supreme Court does not act in a vacuum, and that the great powers of the federal government to regulate interstate commerce, for example, is closely related to commercial law and economic developments in the states. In some instances, the high court reflects trends already apparent at the state level; in other cases, its decisions determine what happens in state law.