Stuart, the earliest reliable biographer of Hale, in writing of spies says: "The exigency of the American army which we have just described, would not permit the employment, in the service proposed, of any ordinary soldier, unpracticed in military observation and without skill as a draughtsman,—least of all of the common mercenary, to whom, allured by the hope of a large reward, such tasks are usually assigned. Accurate estimates of the numbers of the enemy, of their distribution, of the form and position of their various encampments, of their marchings and countermarchings, of the concentration at one point or another, of the instruments of war, but more than all of their plan of attack, as derived from the open report or the unguarded whispers in camp of officers or men,—estimates of all these things, requiring a quick eye, a cool head, a practical pencil, military science, general intelligence, and pliable address, were to be made. The common soldier would not answer the purpose, and the mercenary might yield to the higher seductions of the enemy, and betray his employers."
During the war with the French and Indians, American officers had learned the need of trained men who could keep the commanders informed both of the movements and of the plans of the opposing forces. Washington had learned this unforgetable lesson in Braddock's campaign, and, as full commander and wholly responsible not only for the immediate safety but for the future success of his little army, he realized the necessity of obtaining the most accurate information possible.
A corps collected from the best men in the army was organized, and its command was given to Lieutenant Colonel Thomas Knowlton. He had gained experience as a ranger in the French and Indian War, and was noted for his coolness, skill, and bravery at Bunker Hill. One hundred and fifty men and twenty officers were considered sufficient for the work assigned to this special corps, known as Knowlton's Rangers. They were divided into four companies. Two of the captains of these men were chosen from Knowlton's own regiment; the other two—one of them Nathan Hale—were from other companies. There can be little doubt that Nathan Hale was proud of his enrollment in this brave corps.
After Hale's services were ended, one brief record remained of "moneys due to the Company of Rangers commanded late by Captain Hale." After the 1st of September, about which time this company of Rangers was organized, it was constantly on duty wherever its services were required, and one can easily imagine Nathan Hale's enthusiasm in his enlarged duties.
Knowlton spoke to some of his officers of the wishes of the commanding general for some one to enter upon this special secret service,—wishes that so appealed to Hale that he at once seriously considered offering himself for the hazardous undertaking.
Captain Hull, two years his senior in age, and one year in advance of him in Yale, a close friend while in college and during their subsequent days, shall describe the personal interview between himself and Captain Hale in regard to this matter. It is said that many remonstrated with Hale at his decision, but Hull's statement shows the arguments of a practical man against which Hale had to contend.
In his memoirs Captain Hull writes thus of his last interview with Captain Hale:
"After his interview with Col. Knowlton, he repaired to my quarters and informed me of what had passed. He remarked 'I think I owe to my country the accomplishment of an object so important, and so much desired by the commander of her armies—and I know of no other mode of obtaining the information than by assuming a disguise and passing into the enemy's camp.'
"He asked my candid opinion. I replied that it was an act which involved serious consequences, and the propriety of it was doubtful; and though he viewed the business of a spy as a duty, yet he could not officially be required to perform it; that such a service was not claimed of the meanest soldier, though many might be willing, for a pecuniary compensation, to engage in it; and as for himself, the employment was not in keeping with his character. His nature was too frank and open for deceit and disguise, and he was incapable of acting a part equally foreign to his feelings and habits. Admitting that he was successful, who would wish success at such a price? Did his country demand the moral degradation of her sons, to advance her interests?
"Stratagems are resorted to in war; they are feints and evasions, performed under no disguise; are familiar to commanders; form a part of their plans, and, considered in a military view, lawful and advantageous. The tact with which they are executed exacts admiration from the enemy. But who respects the character of a spy, assuming the garb of friendship but to betray? The very death assigned him is expressive of the estimation in which he is held. As soldiers, let us do our duty in the field; contend for our legitimate rights, and not stain our honor by the sacrifice of integrity. And when present events, with all their deep and exciting interests, shall have passed away, may the blush of shame never arise, by the remembrance of an unworthy though successful act, in the performance of which we were deceived by the belief that it was sanctioned by its object. I ended by saying that, should he undertake the enterprise, his short, bright career would close with an ignominious death.