What major contribution did Wernher von Braun make after World War II?

Wernher von Braun's major contribution after World War II was his leadership in the US rocket program. After the war, he and many of his colleagues were brought to the United States as part of Operation Paperclip to leverage their expertise in rocketry. Von Braun played a crucial role in developing the Redstone and Saturn rockets, which were vital for the U.S. space program, particularly in achieving the goal of landing a man on the Moon.

His work culminated in the successful Apollo missions, where the Saturn V rocket was instrumental in sending astronauts to the Moon. Von Braun's vision, engineering skills, and leadership were essential in advancing the United States' capabilities in space exploration, making him a key figure in the history of aerospace.