Short answers, pulled from the story.
German chemist Martin Heinrich Klaproth discovered uranium in 1789 while working in his experimental laboratory in Berlin. He named the element Uranit after the planet Uranus, which had been discovered eight years earlier by William Herschel. He later renamed it Uranium to conform to the naming standard.
Eugène-Melchior Péligot isolated the first sample of uranium metal in 1841. He was a Professor of Analytical Chemistry at the Conservatoire National des Arts et Métiers in Paris who isolated the metal by heating uranium tetrachloride with potassium. This isolation allowed scientists to study the properties of the element in its pure form.
Henri Becquerel discovered radioactivity by using uranium in 1896. He made the discovery in Paris by leaving a sample of a uranium salt on top of an unexposed photographic plate in a drawer and noting that the plate had become fogged. This finding revealed that uranium emitted energy without any external stimulus.
Alfred O. C. Nier separated the world's first uranium-235 sample on the 29th of February 1940. He used an instrument he built at the University of Minnesota to separate the sample in the Tate Laboratory. John Dunning confirmed the sample to be the isolated fissile material on the 1st of March 1940 using Columbia University's cyclotron.
French physicist Francis Perrin discovered fifteen ancient natural nuclear fission reactors in 1972. These reactors are located in three separate ore deposits at the Oklo mine in Gabon, Africa. The ore deposit is 1.7 billion years old and the reactors operated for hundreds of thousands of years.
The United States detonated the uranium-based device Little Boy over Hiroshima, Japan on the 6th of August 1945. This event marked the first use of a nuclear weapon in war with a yield equivalent to 12,500 tonnes of TNT. The blast and thermal wave destroyed nearly 50,000 buildings and killed about 75,000 people.