Abstract
President Franklin Roosevelt set out to establish popular support for an interventionist foreign policy designed to insure the survival of Great Britain as the key component of American national defense. To overcome the prevailing isolationist viewpoint, FDR educated the people of the immoral character of Nazi Germany and provided necessary understanding of unfolding events. He generated sufficient public support to provide legitimacy for his actions in mobilizing the nation and engaging in an undeclared war in the North Atlantic. FDR's speeches, public opinion polls, and newspaper accounts are herein examined within their historical context. The evidence supports the conclusion that Roosevelt was successful in shifting public opinion. So much so, that succeeding presidents used the foundation FDR laid to fight the Cold War.