Though Dietrich continued to appear in movies directed by the likes of Alfred Hitchcock, Fritz Lang, Orson Welles, and Billy Wilder, she found a new passion in supporting the war effort. She and Wilder, as well as several other Germans, created a fund to help Jews and other dissenters in their escape from Germany. Her entire salary for Knight Without Armor (1937) was used to help refugees. She renounced her German citizenship when she officially became an American citizen in 1939, and became one of the first actresses to help sell war bonds in 1941. Dietrich also entertained as part of the USO, traveling to Algeria, Germany, Italy, the United Kingdom, and France.
