Abraham Lincoln's lost speech

In 1856, Abraham Lincoln gave a speech so inspiring, so captivating, so compelling-... that every reporter present forgot to take notes, and everyone who attended, lacking a written record, eventually forgot about the speech's content, too.

The speech was so compelling, in fact, that it is often credited with helping to launch Lincoln's national career (like Barack Obama's 2004 speech at the DNC). There's even a historical marker commemorating the spot where it occurred.That the speech was so important, though, makes it all the stranger that it was "lost." From Wikipedia:

The speech known as Abraham Lincoln's "Lost Speech" was given on May 29, 1856, in Bloomington, Illinois. Traditionally regarded as lost because it was so engaging that reporters neglected to take notes, the speech is believed to have been an impassioned condemnation of slavery. It is possible the text was deliberately "lost" owing to its controversial content.

There are no known transcripts or written accounts of the Lost Speech, other than a brief summary in the local press. Eyewitnesses have offered snippets of some of Lincoln's content that day. William Herndon asserted that some of Lincoln's House Divided Speech was not based on new concepts at the time of its delivery. He wrote that Lincoln's "house divided against itself cannot stand" originated with the famous Bloomington speech of 1856.

Others speculate, of course, that listeners were merely distracted from the content of the speech by Lincoln's notoriously scratchy voice. You can find out more here.