When did the public officially know about the Manhattan Project?

Question:I know the project was turned over to the government in 1947 as the result of new law, but when the public find out about the details of the project that had been going on?

Best Answer - Chosen by Asker: I know the project was turned over to the government in 1947 as the result of new law, but when the public find out about the details of the project that had been going on?

The whole thing was top secret during the war. My Dad used to say that he walked past the football stadium under which the first sustained chain reaction took place everyday on his way to work, and never knew what was going on.

Harry Truman, Vice President no less, knew nothing about it until after FDR died.

A story in the Chicago Tribune dated August 7, 1945 says that General Groves had been head of the Manhattan Engineer District for the last 3 years and had reported to only the Secretary of War and Chief of Staff. The details in the story include that he was responsible for building three bomb production plants and the cost was 2 billion dollars.

This was the day after Hiroshima, two days before Nagasaki.

Manhattan Project was one of the most secret US project in World War II era. Public, let alone majority of government officials, were aware of the project. Few US military leaders were informed of destructive bomb when they were spearheading to Japan after Nazi Germany fell to Allies.