My dad saved up all through high school to tour Europe after graduation, and set sail with his dad in June of 1939 on a tramp steamer. He and his dad were awakened in Cologne at 1AM on August 29 by the sound of the Wehrmacht marching east, which lasted till daybreak. They decided to "get outta Dodge" ASAP, which turned out to be in the form of a fast British freighter out of Williamshaven for New York. They arrived on September 10 after dodging a torpedo somewhere west of Ireland.
Any doubts they may have held about Hitler's evil were dispelled by that experience and what they had observed of Nazi propaganda and discrimination against Jews, the activities of the Nazi party, the Hitler Youth, and Hitler's rhetoric and annexations.
My dad is rolling over in his grave now as he prophesied (correctly) that Barrack Obama would be a bad choice for president, as he would unknowingly set the stage for a demagogue to follow.
Cheers,
Wes