Youngstown Sheet & Tube Co. v. Sawyer
343 U.S. 579 (1952), held unconstitutional the president's seizure of the strike-threatened steel industry during the Korean War. President Truman had based the executive order on his constitutional power as commander in chief, but the Court ruled that the president exceeded his authority in seizing private property. Even in a time of war, it ruled, only Congress is able to authorize a lawful seizure (and then must pay proper compensation).
Seen and Heard
What made you want to look up Youngstown Sheet & Tube Co. v. Sawyer? Please tell us where you read or heard it (including the quote, if possible).