This article focuses on the months before the Spanish-American war began in April 1898 and addresses two related questions: first, why was the opposition to the war so strong in the United States; second, why did it not prevail? To explore these questions, the papers of the McKinley administration are examined, along with the Congressional Record and forty-one US newspapers, as well as twelve major European newspapers (British, French, German and Spanish) and the relevant documents from the British and Spanish archives. It is only in the press that one can find a coherent, well-articulated and explicit explanation of the antiwar position.