When Thomas Jefferson struck a deal for the Louisiana Purchase in 1803, he knew he was adding a new national power to those specified in the Constitution, but he also believed his actions were in the nation's best interest. His successors would follow his example, setting their own constitutional precedents. Tracing the evolution and expansion of the president's formal power, Untrodden Ground reveals the president to be the nation's most important law interpreter and examines how our commanders-in-chief have shaped the law through their responses to important issues of their time.

...