Dominguez shows that for more than a century members of Congress defined the commander in chief’s authority narrowly, similar to that of any high-ranking military officer. But in a wave of nationalism during the Spanish-American War, members of Congress began to argue that Congress owed deference to the commander in chief. They also tended to argue that a president of their own party should have broad war powers, while the powers of a president in the other party should be defined narrowly. Together, these two dynamics suggest that the conditions for presidentially dominated modern constitutional war powers were set at the turn of the twentieth century, far earlier than is often acknowledged.