Article 1, Section 10 contains the most significant limits on state power found in the main text of the U.S. Constitution. Chief Justice John Marshall, perhaps the most important Justice in U.S. history, used this provision a number of times in a number of significant decisions to limit state power. These decisions effectively enhanced the power of our new federalist form of government. This book delves into the modern issues pertaining to state limitations by tracing its history and looking at today's most important factors. This work makes a valuable contribution to the understanding of the U.S. Constitution by detailing the most significant limits on state power. The many provisions studied in the book provide insights into the various aspects of constitutional interpretation. Coverage includes: ex post facto laws; prohibition against bills of attainder; the import export clause; the Dormant Commerce Clause; and limits on a state's ability to retroactively impair contracts.