From Diary of the American Revolution, Vol II. Compiled by Frank Moore and published in 1859.
October 20.—Governor Johnstone, says a writer in England, has received a letter from Sir George Brydges Rodney, from New York, containing the following, amongst many other authentic particulars, late discovery of Arnold’s plot. He says that the miscarriage of the plan was owing entirely to delay; for that Major Andre had acted as valet de chambre to Arnold for some time, and had been twice backward and forward from New York to Washington’s camp. His detention was owing entirely to accident, and a want of presence of mind; for after he had been seized by the three stragglers who first took him, they suffered him to go; but one of them stopped the others, and insisted upon going after him again, from a conviction that there was something suspicious about him. When they again took him, either from want of recollection, or lest it might occasion suspicions injurious to Arnold, he did not produce a pass from that general which he had in his pocket, but imprudently offered, first his gold watch, and then his purse, which confirmed their suspicions. As soon as he was brought to General Washington, and his person identified, the general, after consulting with M. De Rochambeau, sent his compliments to Arnold, who had the command of five forts, amongst which were the important ones of West Point and Stony Point, signifying their joint intention of visiting him the next day, with a request that his troops, consisting of twenty-seven hundred men, might be drawn out. Arnold at that time not suspecting a discovery, returned a willing answer; but Washington’s aide-de-camp unguardedly dropping some expressions of a spy being taken, and great discoveries being made in the camp, Arnold took the alarm, and escaped precipitately in a whale-boat. General Washington, immediately on his escape, put General Lord Stirling, seven colonels, and two members of Congress, under an arrest. As soon as Sir Henry Clinton was apprised of Major Andre’s situation, he sent General Robertson with a flag of truce, to obtain his release on terms proposed by him, or at least to spare his life; but General Washington, acting conformably to all the rules of war, said he could consider him in no other light than a spy, and that it was impossible to relax from his sentence.1
1 Upcott, vi. 143.