An American physicist stands next to the world's first atomic bomb

The New York Roots of The Manhattan Project

On July 16, 1945 at exactly 5:29:45 a.m., the world entered the unprecedented atomic age with the successful testing of the most powerful weapon known to man.

"Gadget," the first atomic bomb, was born out of the Einstein-inspired Manhattan Project, and was detonated in the desert near Alamogordo, New Mexico.

Overseeing the project was US Brigadier-General Leslie Groves and Los Alamos director and American physicist Robert Oppenheimer.

Designed and launched under Oppenheimer's chosen codename "Trinity" — inspired by a poem by John Donne — the original $6,ooo program budget skyrocketed to a cool $2 billion after Einstein raised multiple concerns that the Nazi's were close to perfecting their own game-changing weapon.

gadgetUS Department of Energy

The explosion vaporized the steel tower, sent a massive shockwave across the desert sand, and produced a mushroom cloud soaring 40,000 feet into the air, according to the Department of Energy.

Immediately after the blast, Oppenheimer reportedly exclaimed, "it worked!"

On August 6, 1945, the US dropped a 5-ton atomic bomb on the Japanese city of Hiroshima. The blast killed 80,000 people immediately and leveled four square miles of the city.

Related: Look back at the effects of the atomic bomb dropped on Hiroshima:

13 PHOTOS
Looking back: Atomic bomb dropped on Hiroshima
See Gallery
An American physicist stands next to the world's first atomic bomb
UNSPECIFIED - CIRCA 1754: Hiroshima after the dropping of the atom bomb in August 1945. USAF photograph. (Photo by Universal History Archive/Getty Images)
UNSPECIFIED - CIRCA 1754: Survivors of the explosion of the Atom bomb at Hiroshima 1945 suffering the effects of radiation. ICRC photograph. (Photo by Universal History Archive/Getty Images)
World War II, after the explosion of the atom bomb in August 1945, Hiroshima, Japan. (Photo by: Universal History Archive/UIG via Getty Images)
World War II, after the explosion of the atom bomb in August 1945, Hiroshima, Japan. (Photo by: Universal History Archive/UIG via Getty Images)
World War II, firestorms after the explosion of the atom bomb in August 1945, Hiroshima, Japan. (Photo by: Universal History Archive/UIG via Getty Images)
1945: Atomic bomb damage at Hiroshima with a burnt out fire engine amidst the rubble. (Photo by Keystone/Getty Images)
World War II, Human shadow on bank steps, in Hiroshima after the explosion of the atom bomb in August 1945, Japan. (Photo by: Universal History Archive/UIG via Getty Images)
World War II, after the explosion of the atom bomb in August 1945 Hiroshima, Japan. (Photo by: Universal History Archive/UIG via Getty Images)
World War II, shadow of a tap on a pipeline at Hiroshima after the explosion of the atom bomb in August 1945, Japan. (Photo by: Universal History Archive/UIG via Getty Images)
6th August 1945: The twisted wreckage of a theatre, located 800 metres from the epicentre of the atomic explosion at Hiroshima. (Photo by Keystone/Getty Images)
HIROSHIMA, JAPAN: This September 1945 file picture shows the remaining of the Hiroshima Prefectural Industry Promotion Building, known as the Atomic-Bomb Dome, which was later preserved as a monument. (Photo credit should read AFP/Getty Images)
HIROSHIMA, JAPAN - NOVEMBER 26: Atomic Bomb Dome stands among fallen autumn leaves at the Hiroshima Peace Memorial Park on November 26, 2014 in Hiroshima, Japan. (Photo by Yuriko Nakao/Getty Images)
HIDE CAPTION
SHOW CAPTION
of
SEE ALL
BACK TO SLIDE

Three days later, the US dropped another bomb on Japan's Nagasaki, killing about 40,000 people instantly; thousands more would die of radiation poisoning.

Eight days later, Japan informally surrendered to the Allied forces, effectively ending World War II.

NOW WATCH: Animated map shows every nuclear-bomb explosion in history

See Also:

SEE ALSO: An unsettling photo of a US physicist cheerfully holding the 'Fat Man' atomic bomb's core

Read Full Story

Sign up for Breaking News by AOL to get the latest breaking news alerts and updates delivered straight to your inbox.

Subscribe to our other newsletters

Emails may offer personalized content or ads. Learn more. You may unsubscribe any time.