The Posse Comitatus Act (PCA) is often the so called linchpin that bars the use of our military forces to support and enforce civil law within the borders of the United States. This act has in effect, denied the citizens of the United States the utmost protection they should be afforded by the federal government by restricting the use of Department of Defense assets to be used as force multipliers to our federal law enforcement and intelligence agencies. The United States will be required to once again do more with less as federal spending is decreased on not only homeland defense, but its security as well. The Federal Government will need to effectively utilize the combined resources of its numerous departments in order to accomplish this endeavor. Currently, the misinterpretation of the Posse Comitatus Act and the addition of subsequent restrictions have degraded our ability to properly protect the homeland. The Posse Comitatus Act is an ambiguous and highly misinterpreted law that needs to be rescinded and replaced with a new law that clearly identifies the terms in which the use of military forces in protecting the homeland is appropriate. This book focuses on the use of military forces in domestic affairs within the historical context of posse comitatus within the United States, the subsequent Posse Comitatus Act of 1878, the interpretation of the Posse Comitatus Act since its passage, and its current influence on the United States' ability to defend its homeland. This work is a historical case study of the Posse Comitatus Act to include recommendations for how best to use our nation's military forces in a non-wartime environment in order to better ensure our nation's security in a whole of government approach.