1863 photo of John L. Burns, War of 1812 veteran and sharpshooter in the Battle of Gettysburg.
Burns, born ca. 1793, was a 70-year-old veteran of the War of 1812 when he was wounded in the Battle of Gettysburg, having volunteered his services as a sharpshooter to the Federal Army. He died of pneumonia in 1872.
And from the comments:
Mr Burns’ flintlock is at half-cock with the frizzen down, ready to ready to fire.