Read the excerpt from "Tools of the Spymaster." In the summer of 1777, British General Sir Henry Clinton, in New York City, had to keep in touch with General John Burgoyne, whose troops were heading down the Hudson Valley, and with General Sir William Howe, who was supposed to link up with Burgoyne but instead had chosen to take Philadelphia.

Howe believed that "friends of [the British] Government" along the Hudson would make Burgoyne's task easy. But along the Hudson there were also many enemies of the British. A Peekskill man, for example, although paid to be a courier for Burgoyne, handed the general's message to the Americans. Other British couriers who rode south were never heard from again.