Post-WWII US program that secretly recruited 1600 Nazi scientists — including Wernher von Braun and the rocket team that put Apollo on the moon.
From Wikipedia
Operation Paperclip was a secret United States intelligence program in which more than 1,600 German scientists, engineers, and technicians were taken from former Nazi Germany to the US for government employment after the end of World War II in Europe, between 1945 and 1959; several were confirmed to be former members of the Nazi Party, including the SS or the SA.