From Superfortress to Poseidon: Strategic Nuclear Delivery Systems of the United States of America from 1945 to 1972
West Point Press
"After the delivery of “Little Boy” and “Fat Man” on Hiroshima and Nagasaki in August 1945, the world’s focus quickly turned from conventional armaments to nuclear weapons. Four years, one month, and thirteen days after “Trinity,” the United States’ first nuclear test, the Soviet Union detonated their first nuclear device code-named “First Lightning”. With United States’ monopoly on nuclear weapons a thing of the past, the two countries began a massive build-up of nuclear armament, beginning in the early 1950s to the signing of the Strategic Arms Limitation Talks Agreement on May 26, 1972."
Lee, Seanan. “From Superfortress to Poseidon: Strategic Nuclear Delivery Systems of the United States of America from 1945 to 1972.” West Point Undergraduate Historical Review. Volume 12 (Spring 2022): 45-66.