(CNN)"Abraham Lincoln died this morning at 22 minutes after seven."
Ten words that changed the course of history. It was written on a telegram on April 15, 1865 -- the morning after Lincoln was shot by John Wilkes Booth at Ford's Theatre in Washington, D.C.
The telegram, which notified the public of the President's death, goes up for sale Monday, the anniversary of that date.
"This document was the official word to the nation that the President had died," said Nathan Raab, the Raab Collection's president. "It is truly one of our great finds."
The Raab Collection is a historical documents dealer. It said the death notice was thought lost forever until it was recently discovered in a Civil War general's estate.
The Raab Collection says news of Lincoln's death was dictated by Secretary of War Edwin Stanton, who stood watch over the president. Chief telegraph officer Thomas Eckert then passed on the telegram to Maj. Gen. John Dix, who disseminated it to the press.
The telegram is valued at $500,000, Raab says.