April 21, 1951 — Codename Easy, an A-bomb, is tested at the Enewetak Atoll

The nuclear tests at Enewetak were part of a series called Operation Greenhouse. The bombs in the Greenhouse series were smaller in size, weight and amount of fissile material used. At the time they were made, the US had already begun creating a stockpile of such weapons in advance of testing.

Operation Greenhouse was not the first test of the Eisenhower administration, but it was the first to take place at the Pacific Proving Grounds (which were, technically, not even US territory, being instead land held under a United Nations mandate). The aggressive testing schedule of 1951 was largely in response to Soviet Union’s first successful nuclear test in August 1949.

Greenhouse George.jpg
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As mentioned in:

Dr Jeep — Sisters of Mercy

1951 — Ray Bradbury publishes “The Illustrated Man”

First published in February of 1951 (the exact day is, alas, lost to history), ‘The Illustrated Man’ is a volume of some eighteen short stories, loosely connected by a framing device: the title character. The Illustrated Man is a carny worker, and each of the stories in the book is represented by one of his tattoos.

Only one of the stories was original to the book, although several of them were revised by Bradbury to better fit the frame concept.