Armistead and Hancock were both career soldiers, and before the Civil War they were friends when both were U.S. Army officers in California. Both were also Freemasons.

When the Confederate attack reached the Union line at Gettysburg, there was fierce fighting. General Armistead was shot twice, and as he went down he gave a Masonic sign asking for assistance. A fellow Mason, a Union officer named Henry H. Bingham, then a Captain, later a higher officer and then a very influential Congressman, came to Armistead's assistance and offered to help. Armistead reportedly asked to see and talk with his friend General Hancock, but he was told that Hancock had been very badly wounded just a few minutes earlier. Union Brother Bingham then helped Confederate Brother Armistead off the field and to a hospital, but Armistead died two days later. General Hancock, to the surprise of many, recovered and resumed his command later in the Civil War.

This incident, of a Freemason who was a Union officer helping a Freemason who was a wounded Confederate officer, is one of the greatest examples of the ideals of Freemasonry in action. In 1993, the Grand Lodge of Pennsylvania completed and dedicated a monument on the Gettysburg National Cemetery, with the cooperation and support of the United States government, that shows Brother Bingham, a Union officer, assisting Brother Armistead. This statue is extremely dramatic, and it is called the "Masonic Friend to Friend Masonic Memorial."

In the words of Sheldon A. Munn, one of the Freemasons who helped bring about the construction of this monument:

"The 'Friend to Friend Masonic Memorial,' at Gettysburg will help demonstrate to the world that Freemasonry is, indeed, a unique fraternity; that its bonds of friendship, compassion and brotherly love withstood the ultimate test during the most tragic and decisive period of our nation's history; it stood then as it stands now, as 'A Brotherhood Undivided!'"