The American general was desperate. The last time he had faced his enemy counterpart, who considered one the best tacticians in the world, he and his men had barely escaped with their lives and had given up crucial territory during the withdrawal. He knew that he could be engaging in a second battle at any time and that if he were to be victorious, he needed crucial information on the enemy’s position and plans.

He knew that in order to get this intelligence, he would need to get someone into enemy territory. He needed a spy. He put out the call, and one man immediately volunteered. The general was George Washington, his enemy was General William Howe, and the battle would take place on September 16, 1776, at Harlem Heights, Manhattan. The spy who stepped forward was Nathan Hale.

Almost everyone knows the fate of Hale. Receiving his orders from Washington, he set out on his mission and successfully penetrated British lines, posing as a Dutch schoolmaster. For a week, Hale carried out his mission, gathering information on enemy positions before attempting to make his way back to American lines. He was almost home free when he was set upon by a British patrol, which discovered the documents that he had drawn and notes that he had taken.

According to an article in the Library of Congress’s online publication, “America’s Library,” it is believed that Hale was betrayed by a cousin who sympathized with the British and was, at the time, under Howe’s command. Whatever the reason, Hale is said to have uttered the famous epitaph, “I only regret that I have one life to give for my country,” before he was hanged on September 22, 1776. He was 21 years old.

Although by far the most famous of the Revolutionaries ragtag and unorganized intelligence operators, Hale was far from the only one. Though not an intelligence operator in the traditional sense, Paul Revere, after learning of British General Thomas Gage’s plans for a surprise midnight raid to seize the weapons of rebel colonists in Lexington, Massachusetts, determined to warn patriot leaders John Hancock and Samuel Adams of the impending attack. He borrowed a horse and rode off into the night of April 18, 1775.

Even his wife, Rachel, got in on the game. Overhearing that the British were on to her husband, she attempted to contact him via a wax-sealed letter containing a warning and 125 British pounds. The problem for Rachel was that the British had their own intelligence network that was quite extensive and well organized, and unfortunately, Rachel passed the letter to one of its operators — Dr. Benjamin Church.

Church promptly turned the letter over to British authorities. Revere was able to deliver his warning to the rebel leaders, but his “The British are coming!” midnight hollering was cut short when he was stopped by a British patrol. Fortunately, in their haste to join the impending fight at Lexington, they let him go.

Probably the most infamous British spy was Benedict Arnold. Arnold began his military career as a militia captain. He soon gained a reputation as a ferocious fighter and tactician, but also as a divisive character making many enemies among his own men. According to a biography, Arnold was even brought up on charges of misappropriation of funds and faced a court-martial.

Despite these setbacks, his career continued to be successful. In 1778, Arnold was appointed as the military commander of Philadelphia after the British withdrew their troops. It was there that he met his second wife, Peggy Shippen, and his career as a British spy began. Shippen was the daughter of a loyalist sympathizer, and during her time in Philadelphia, she met and maintained contact with many British officers, including one Major John Andre. Shippen introduced her husband to Andre and the two struck up a friendship via correspondence.

By the summer following their initial meeting, Arnold was providing the location of supply depots and troops to the British. In August 1780, Arnold was made post commander for West Point, and he immediately began systematically weakening the fort’s defenses, while at the same time transferring his assets from America to England.

In September 1780, a few days after Arnold and Andre met face-to-face, Andre was captured, and with him, plans to lay siege to and take West Point. It was deduced that Arnold was a spy, and in what could be called an early special operations capture mission, General George Washington ordered a group of soldiers, dressed as civilians, to infiltrate New York and kidnap Arnold. However, he escaped and fled to England.

Benedict Arnold was eventually sent back to the colonies, this time as a general in the British Army. He was hugely successful, and after the war returned to England with his family. He became a businessman in Canada, where he was ironically captured and imprisoned by the French on suspicion of spying. He died in 1801 at the age of 60 in London, and his name has become synonymous with real and perceived acts of betrayal ever since.

Even those in positions of political and social power were not above spying in the interest of national security. Benjamin Franklin was an original member of the Committee of Secret Correspondence (a forerunner to today’s CIA). The Committee was created and charged by the Second Continental Congress in 1775 with gathering intelligence and “corresponding with our friends in Great Britain and other parts of the world” to gain information that would be helpful to the American cause and to forge alliances with foreign countries.

Ironically, Franklin’s own son, William, spied on his father as a loyalist and reported to British authorities. The American Revolution also saw some of the first recorded uses of intelligence techniques, which are somewhat still in use, such as invisible ink, cipher keys, and dead drops.

The American Revolution was not the only contemporary conflict requiring the use of spies to gather intelligence. A few years after the American colonists decided to fight for their independence, a group of like-minded men and women in France made the choice to throw off the yoke of what they saw as tyranny from the ruling monarchs.

One of these revolutionaries was Bertrand Barere, who is most famous for ending a speech related to his vote in favor of executing King Louis XVI with the words, “The tree of liberty grows only when watered by the blood of tyrants.” Barere, who was notorious for switching sides, was also used as a spy by Napoleon. Yet, as is often the case in the business of espionage, as soon as his usefulness had run out, Napoleon had him thrown in prison on suspicion that he might use his newfound skills against his former master.

Editor’s Note: This article, which was originally published in 2015, is part of a series. You can read part I here and part II here.