In an article published on November 19 by the Philadelphia Inquirer, Civil War Era Studies professor Allen Guelzo discusses the people who attended Lincoln's Gettysburg Address and the accounts that they left behind.
From the Philadelphia Inquirer:
Who heard Lincoln deliver the Gettysburg Address?
The short answer is the 15,000 people who crammed into the small town of Gettysburg on Nov. 19, 1863, for the dedication of the Soldiers' National Cemetery. That included three Cabinet secretaries, nine state governors, the representatives of France and Italy, the U.S. Marine Band, and "citizens from every quarter thronging into the village in every kind of vehicle. ..."
Of course, if Thomas Alva Edison had been able to move up his invention of the phonograph by just 14 years, the whole country might have been able to listen to Lincoln deliver his Gettysburg Address. (Edison made his first recording of a human voice on a tinfoil cylinder in 1877.) Still, we have a rich collection of descriptions of Abraham Lincoln as a speaker to fill that gap - although none of them, surprisingly, describe an operatic baritone or a political crowd-pleaser.