General Groves oversaw the construction of the Pentagon, but more notably, directed the Manhattan Project that developed the atomic bomb during World War II.
Groves died on July 13, 1970, at 73 years of age. He is interred in Arlington National Cemetery, next to his brother, Allen, who died of pneumonia in 1916. Grace, his wife, was interred next to Groves in 1986.
The tombstone marks his participation in the Manhattan Project along with the insignia. The grave faces the Pentagon, which can be seen in the distance.