This is the first in an eight-part series examining the Declare War Clause of the U.S. Constitution. It explores the complex and evolving interpretation of this clause, focusing on the division of war powers between Congress and the President. We will detail the historical context, relevant Supreme Court cases, and the practical application of the clause throughout U.S. history, including the use of declarations of war and authorizations for the use of military force. The series will analyze various conflicts, highlighting the interplay between executive and legislative branches in wartime decision-making. Finally, it emphasizes the broad scope of Congressional war powers while acknowledging constitutional limits on this authority.