July 1, 1916, was the first day of the Battle of the Somme. In a few hours the Allies would suffer over 50,000 casualties as men marched across no man’s land and into a hailstorm of machine gun fire. In the United States, there was a heat wave on the East Coast, and news of a polio outbreak panicked those with children. It was also an election year, and President Woodrow Wilson had decided that his home, Shadow Lawn on the Jersey Shore, would become the summer White House.

“The Philadelphia Bulletin grudgingly admitted, ‘New Jersey will have cause this summer to feel more important than…