It's likely you've noticed the mural on the side of the Spalding House, Crosby, Minnesota. This mural pictures USAF Major David G. Simons, MD on August 19, 1957 when he successfully completed the Manhigh II high-altitude balloon mission.
This flight lasted 32 hours and earned an altitude record of 101,516 feet.
Project Manhigh II, a United States Air Force biomedical research program, investigated the the impact of having humans enter a near-space environment. The insight gained from this mission was highly useful in developing the nation’s early manned spaceflight effort.
The balloon used in the mission was a helium-filled polyethylene balloon, just 0.0015-inches thick. That's about the same thickness of plastic produce bags in grocery stores.
Here's a video of the actual mission:
You can learn more about this fascinating mission at the Soo Line Depot Museum, 101 1st Street NE, Crosby MN, 56441