A doctor\'s account of his frantic efforts to save the life of a fatally wounded president Abraham Lincoln has been rediscovered in the United States, after being lost to history for 150 years. On April 14, 1865, Charles Leale happened to be in the same Washington theater as the US president, watching the play \"My American Cousin,\" when he heard a gunshot and saw a man leap onto the stage. Leale, 23, the first person to tend to Lincoln\'s wounds, documented the tragic encounter in a 21-page handwritten report. A copy of Leale\'s notes from that tragic night found its way to the National Archives, America\'s massive repository of historical documents, where -- until last month -- it had been overlooked for a century and a half. It was found by a researcher with The Papers of Abraham Lincoln Project, a historical group which announced the find this week. \"It is truly a first draft of history,\" Stowell said. The historic document was found by a researcher, Helena Iles Papaioannou, among hundreds of boxes of old medical reports. Lincoln -- who led the country into a bloody civil war, but preserved the union and ended slavery -- was shot by assassin John Wilkes Booth, an actor and Confederate sympathizer. Outraged by the South\'s defeat in the war between southern and northern states, Booth carried out a carefully devised plot to kill Lincoln, the first US president to be assassinated. \"The theatre was well filled and the play of \'Our American Cousin\' progressed very pleasantly until about half past ten, when the report of a pistol was distinctly heard and about a minute after, a man of low stature with black hair and eyes was seen leaping to the stage beneath, holding in his hand a drawn dagger,\" Leale wrote. \"I then heard cries that the \'President had been murdered,\' which were followed by those of \'Kill the murderer\', \'Shoot him,\' etc. which came from different parts of the audience,\" wrote the young physician, who had only received his medical degree about six weeks earlier. \"I immediately ran to the President\'s box and as soon as the door was opened, I was admitted and introduced to Mrs. Lincoln when she exclaimed several times, \'O Doctor, do what you can for him, do what you can!\' I told her we would do all that we possibly could,\" Leale recounted. Booth was tracked down by Union soldiers and was shot and killed on April 26, 1865. Lincoln aficionados and scholars specializing in the Civil War era called the document an astonishing find of tremendous historical import. \"What\'s exciting about it is its immediacy and its lack of sentimentality,\" said Daniel Stowell, director of the Papers of Abraham Lincoln Project, which is carrying out research on documents written by or to America\'s 16th president. \"You get the sense of the helplessness of the doctors,\" he added. The document can be viewed at the group\'s website http://www.papersofabrahamlincoln.org/New_Documents.htm. Leale\'s account was written just hours after Lincoln was shot in his balcony theater box about 12 meters (40 feet) from where the young physician was seated. He describes first examining Lincoln, and then moving him to a boarding house across the street from Ford\'s Theatre -- which still stands, a few blocks from the White House. \"We placed the President in bed in a diagonal position; as the bed was too short,\" Leale recounted. \"At 7:20 am he breathed his last and the spirit fled to God who gave it.\" More than two years after Lincoln\'s death, in July 1867, Leale sent a copy of his report, written longhand by a secretary, to a US congressional committee that was conducting an investigation of the president\'s assassination. In subsequent years, he said little else about his heroic efforts that night to save America\'s dying leader.