Manhattan Project Pin

The Manhattan Project was the effort which led to the development of the atomic bomb by the US during WW-II.  Though the eventual use of the bomb on Hiroshima and Nagasaki remains a subject of controversy some 60 years later, there is little doubt that the number of casualties on both sides would have been far greater if an invasion of the Japanese home islands had actually been necessary. 

Japan was engaged in their own atomic bomb development project, and was close to a successful conclusion when the first bomb fell on Hiroshima.  Had Japan reached the goal first, there is no doubt that they would have used the bomb on US cities.

After the surrender of Japan, and the disbandment of the project, each of the approximately 132,000 project members received one of these lapel pins.  The one shown here is Sterling silver, which indicated service beyond one year.  For one year or less, the pin was bronze.  It is about 3/4 inch in diameter.

Read more about the Manhattan Project at these sites (and check their links pages for much more information):

Atomic Heritage Foundation

Manhattan Project Heritage Preservation Association