In the summer of 1940, after the fall of France to Hitler's advancing troops, opponents of President Franklin D. Roosevelt's foreign policy organized their many divergent groups into the powerful and vocal America First Committee (AFC). The committee coordinated all anti-interventionist efforts to block Roosevelt's proposals for providing lend-lease assistance abroad, arming merchant ships, and escorting war supplies to Allied ports. The AFC held huge public rallies, distributed tons of literature, supplied research data to members of Congress, and sponsored coast-to-coast radio speakers to support the anti-interventionist position. By the time the Japanese bombed Pearl Harbor on December 7, 1941, the AFC had 450 units and at least 250,000 members. Many historians believe the AFC's massive and efficient campaign was responsible for delaying US entry into World War II. In Danger Undaunted , based on 338 manuscript boxes deposited in 1942 in the Hoover Institution Library & Archives, conveys the logic, complexity, and passion of the anti-interventionist movement. The book illustrates the dramatic impact this well-organized and vocal group had on US foreign policy and on the political behavior of many of America's most prominent statesmen of the prewar years.