Conflicts between the executive and legislative branches often revolve around disagreements about the powers granted to the president by the Constitution, especially powers related to armed conflict. The War Powers Act of 1941, which was also known as the First War Powers Act, allowed President Franklin Roosevelt to respond immediately after the attack on Pearl Harbor by essentially declaring war on Japan.

Roosevelt knew that he needed to convince the American people that his declaration was justified, however. In advance of one of his "fireside chats" or radio addresses to the nation, Roosevelt asked citizens to have a world map in front of them as they listened to him speak. He told his speechwriters this:

I want to explain to the people something about geography—what our problem is and what the overall strategy of the war has to be. If they understand the problem and what we are driving at, I am sure that they can take any kind of bad news right on the chin.

A law very similar to the War Powers Act had been passed during World War I. It was called the Departmental Reorganization Act of 1917, and it allowed President Woodrow Wilson to reorganize government agencies "during the continuance of the present war and for six months after the termination of the war by the proclamation of the treaty of peace, or at such earlier time as the President may designate." Using this authority, Wilson created numerous agencies, including the War Industries Board, the National War Labor Board and the Committee on Public Information.

Woodrow Wilson and his War Cabinet

The 1941 War Powers Act went farther than the 1917 act, though. It gave President Roosevelt the authority to organize troops for battle without seeking the support of Congress. The act also granted the federal government other powers that seemed contrary to the Bill of Rights; for instance, it allowed the government to censor mail to and from foreign countries. However, the 1941 act included the same time limit as the 1917 act: Six months after the end of the war, it would no longer be in effect.

In 1942, a Second War Powers Act further strengthened the executive branch's authority during times of war, asserting that private or corporate land could be seized by the government for military purposes. This second act also removed protections on the confidentiality of census data, which allowed the FBI to arrest and imprison Japanese Americans simply because they listed Japan as their ethnic background.

Japanese Americans arrive for Internment processing, from San Pedro at the Pacific Electric Railway (Red Cars) station, in Arcadia, Southern California.	Japanese Americans transplanting celery at the Tule Lake Relocation Center during the Second World War.

While the loss of these citizens' rights was clearly a violation of the Constitution, Congress did not interfere. The Supreme Court also remained mute on the subject, citing its practice of not involving itself with wartime matters. The violation of Constitutional rights represented by Japanese American internment was seen by the courts as secondary to upholding the rights of the executive branch to manage national security.