With the expansion of the federal government since the 1930s and the rise of the United States as a global power in the twentieth century, the need for a powerful president to direct American priorities and policies is clear. In times of national crisis, domestic and international focus on the president becomes even greater, with the widespread expectation that executive leadership is necessary to combat the challenge. The need for checks on that power by other institutions of American government, namely Congress and the courts, also is evident, though the balancing of presidential power typically has not developed in conjunction with its expansion. This edited volume analyses the growth of presidential power from the Civil War era to the present, examining both emergency situations in wartime and developments in non-crisis periods.