Henry Bacon spent most of his life in London and Paris, recording the doings of the moneyed in slick, cheerful canvases. But as a young man he served in the 13th Massachusetts Volunteers in the Civil War and was wounded in action. Early in the war he came upon a huge old chestnut tree, eighteen feet around, stripped of its branches and turned into a signal station—part of a line that ran from the Maryland Heights to Washington. The flagmen, sick of wearying their arms passing along inconsequential news, distilled all the trivia they were being handed into a single serviceable message that became immortal and that gave Bacon the title for his painting: “All Quiet on the Potomac.”