WASHINGTON – The tale of one of President Abraham Lincoln’s last acts — pardoning a soldier due to be executed for desertion — has gone down in U.S. folklore. But it has emerged that the historic document stored in the U.S. national archives is a forgery.

The pardon was said to have been signed by Lincoln on April 14, 1865 — just a few hours before the president left for the theater at which he was then assassinated by John Wilkes Booth.

But Thomas Lowry, an amateur historian, has admitted he changed the document’s date to increase the pardon’s historic importance.