Suspension during the Civil War and Reconstruction
In Ex Parte Milligan 71 U.S. 2 (1866), the Supreme Court of the United States decided that it was unconstitutional for the President to try to convict citizens before military tribunals when civil courts were functioning.

As for WWII, do you think it was right to put all Japanese Americans in concentration camps? If you answer yes then you just confirm yourself to be a fascist.