My mother worked on the Manhattan Project and was so proud of her contribution. She passed away last year at age 95.
Over 500,000 people worked on the Manhattan Project. Approximately 1% of the total workforce.
Mum95 year old uncle (still living) worked on it, too. He was a young mechanical engineer and was a production leader at Oak Ridge on one of the separation lines. He doesn’t think it was much of a big deal. My dad (his brother) was aboard an invasion vessel in the Pacific 70 years ago today. Their lives were intertwined in an interesting way in addition to being brothers.
My dad worked on the Manhattan Project, and was one of the few who actually worked IN Manhattan (at Columbia University). His field was U235/U238 separation.