My grandfather worked on the Manhattan Project and because he died in July 1945, we, his wife, children, and grandchildren never knew what job her performed or what role he had on the project. At the time of this death, everything he did was protected by security. There were clues here and there that what he did appears to have been very secret. My father remembers that his father was doing two jobs on the project and that there was always a security man parked outside the house whenever he was home, something that bothered my grandmother a lot. My uncle wanted to pop into the office to visit his father when he was home on furlough but didn’t know where his father’s office was in Boston. As it turns out, my uncle had to wait for this father outside the 161 Devonshire Street building. When his father emerged, my uncle was introduced to a senior Army official visiting his father. My uncle was later able to use this relationship to extend his furlough for his grandmother’s funeral.
All of this information made for a tantalizing mystery to be researched.
Who Was My Grandfather?
My grandfather was Donald Lewis Macdonald, Sr, frequently referred to by family and friends, as well as in these blog articles, as Mac. He was born on March 5, 1897, in Somerville, Massachusetts, and died on July 8, 1945, at the McGhee-Tyson Airport, Knoxville, Tennessee, of an apparent heart attack at the age of 48. I say ‘apparent’ because that is what it says on his death certificate. There was no autopsy or other work done to confirm the cause of death. His body was taken to a funeral home nearby and shipped home to be buried in the family plot. A representative was sent along with the body to help with the arrangements.

Growing up his seven grandchildren learned that our grandfather worked on the Manhattan Project, the top-secret WWII project to build the atomic bomb. This information was fleshed out over time lacked detail, mostly because our grandfather died in July 1945 and what he did was lost with him. My father knew a few things because he worked as a teenage courier in the Manhattan Project’s Boston office. And there were bits and pieces of information that had been shared with family members or appeared in the letters. Due to the secrecy surrounding the project and everyone working on it, there wasn’t a lot of information that could be shared.
At the time of Mac’s death, my grandmother was also 48, my father was 16, and my uncle was 21 and serving in the Army, the 10th Mountain Division, in Italy. His death was a shock not only to his immediate family, but to friends, and work associates as well. My grandmother kept many of the sympathy cards and letters she received at his death so it is easy to read how people felt at his death. I discussed these cards and letters in The Green Box.