Read the excerpt from “Tools of the Spymaster."

Both the British and the Americans frequently used horseback riders to carry messages, and both sides tried to capture the riders and get the messages. The rider who lost one of Washington's important messages was Tallmadge himself. It happened when Tallmadge and some of his men were attacked by British troops near the Connecticut–New York border. Tallmadge escaped unharmed but lost a saddlebag full of secret papers.

Luckily, Tallmadge's code did not fall into British hands. But among the papers was a letter from Washington in which he carelessly gave the name and address of an agent, George Higday, saying that he was a man who would probably "convey intelligence to me." Higday was arrested, but he had managed to destroy all evidence of spying. That move probably saved him from hanging.

What evidence in the excerpt suggests that being a spy for the Americans could be deadly?

The evidence in the excerpt that suggests that being a spy for the Americans could be deadly is that the spy, George Higday, was arrested, and if he had not managed to destroy all evidence of spying, he probably would have been hanged.