John "Jack" Armstrong was the subject of many stories scattered through the historical record for his part in the wrestling match with Abraham Lincoln in Clary's Grove, Salem Illinois.
Jack was a blacksmith in town and the man whom kept the rowdy Clary Boys in line as best as any one person could. It may have been because Jack was the brother-in-law of John A. Clary that they listened to him. The Clary Boys played their part in the wrestling match by antagonizing the event to take place.
Abe became such a good friend to John and his wife Hannah, that he defended their son "Duff" in a murder trial at the grievous request of Hannah. Based on an eye witness account that there was a full moon the night it happened Abe was able to prove Duff's innocence. He referred to the almanac to prove that there was not a full moon in the sky that night.
That wrestling match between him and Abe led to many a friendship and fond memories as written about by Mr. Lincoln himself in later years.