As members of Congress gathered in April 1917 to decide whether to declare war on Germany, some legislators arrived with battle scars. For Civil War veterans, the memory of that catastrophic war would inform their understanding of a new conflict. But their experience of war was overtaken as 20th century American wars moved offshore. Distance made war a matter of choice in 1917. This lecture will reveal what it would take to generate sufficient support to enter a faraway war: a politics of catastrophe. Dramatic stories of the deaths of small numbers of Americans who chose to cross an ocean war zone ultimately drove the country to commit soldiers to fight in European trenches. Over one hundred thousand American soldiers died. In World War I and after, dramatic events like torpedoed ocean liners were not a president’s sole reason for entering a war. But broad political mobilization and congressional authorization for distant war, in World War I and after, required a politics of catastrophe.