The balloons were weather balloons sent up for high altitude measurements and then balloons for high altitude jumps. Captain Joseph Kittinger jumped from more than 19 miles up as part of Projects Manhigh and Excelsior.
It turned out the UFO stories were good cover for other test flights so the Air Force encouraged them. A magician is skilled in getting you to focus on one hand while they're surreptitiously moving the other.
That’s a load of cow flop.
[The alien stories started from monkeys in space suits.]
Not back in 1947 when the Roswell crash allegedly took place.