After the US Army saw the demonstration of the weapon plans were soon made for it to be used against the Japanese.

The first test of the A-Bomb was made on July 16, 1945 at Alamogordo, New Mexico. Atomic Bomb Facts - 2: The atomic bomb was developed by scientists on the Manhattan Project during WW2.
Its roots lay in a letter Albert Einstein sent to President Franklin Roosevelt. The first atomic bomb dropped in World War II was dropped by the United States, on Hiroshima, Japan. The B-29 and atomic bomb program was originally intended for use on Nazi Germany but Germany capitulated before either was ready, so the program was shifted to the Pacific. The Atomic Bomb was developed during WW2 by scientists working on the top secret Manhattan Project. The bomb, nicknamed “Little Boy”, was dropped by the B-29 Superfortress bomber Enola Gay.And although it took a second atomic bomb to force Japan to surrender, the Enola Gay's name has gone down in history as the plane that was responsible for ending WWII.

80,000 - People who died instantly in Hiroshima, Japan, on August 6, 1945, when the first ever atomic bomb was used in war.

Steaming at high speed, the cruiser delivered the bomb components to Tinian on July 26. On August 6 and 9, 1945, the cities of Hiroshima and Nagasaki were destroyed by the first atomic bombs used in warfare. The effort led to the invention of atomic bombs, including the two that were dropped on the Japanese cities of Hiroshima and Nagasaki, killing or injuring over 200,000 people.These attacks forced Japan to surrender and brought an end to World War II, but they also marked a crucial turning point in the early Atomic Age, raising enduring questions about the implications of nuclear warfare. An atomic bomb is a weapon with huge power created by splitting an atom of the element uranium. World War 2 Atomic Bomb. The scientists who invented the bomb included Robert Oppenheimer, Edward Teller, Rudolf Peierls and many others. Fat Man was in fact the code name of this atomic bomb which was yet again used by the United States against Japan. Three days after the United States dropped an atomic bomb on Hiroshima, a second atomic bomb was dropped on Nagasaki on August 9 – a 21-kiloton plutonium device known as "Fat Man.” On the day of the bombing, an estimated 263,000 were in Nagasaki, including 240,000 Japanese residents, 9,000 Japanese soldiers, and 400 prisoners of war. In 1945, the USA dropped two atomic bombs on Japan, effectively ending World War II. That same day, the uranium target was flown to the island in three C-54 Skymasters from the 509th Composite Group. The core was being readied for transport to Tinian. On 6th August, the bomb was dropped on the city of Hiroshima. With all of the pieces on hand, bomb unit L11 was chosen and Little Boy assembled. It was the first nuclear weapon used in warfare. It exploded 600m (2,000ft) above the city, creating a blast of heat and blinding light. The United States with the authorization of President Harry Truman, dropped an atomic bomb on the people of Hiroshima, Japan on August 6, 1945 and one on Nagasaki, Japan on August 9, 1945. The code name of the uranium-based bomb was "Little Boy."
"Little Boy" was the codename for the type of atomic bomb dropped on the Japanese city of Hiroshima on 6 August 1945 during World War II. It was tasked to create the bomb beginning in 1939. The first atomic bomb test, code-named Trinity took place on July 16, 1945. The third atomic bomb, which was the second plutonium fueled implosion bomb, was already at Tinian. The first atomic bomb ever to be used in a military operation was dropped on the city of Hiroshima, Japan On August 6, 1945 at 8:16:02 a.m. Hiroshima time. The nuclear age began on July 16, 1945, when it … This once classified photograph features the first atomic bomb — a weapon that atomic scientists had nicknamed "Gadget." The first test of the A-Bomb was made on July 16, 1945 at Alamogordo, New Mexico.