In addition to the foregoing, by way of elucidation, it is to be understood by you, that so early as from the latter part of the year 1776, I was always attached to a commanding general; and, in consequence, my knowledge of the officers and their merits was more general than that of almost any other in service. My operations were upon the extended scale, from the remotest parts of Canada, wherever the American standard had waved, to the splendid theatre of Yorktown, when and where I was adjutant-general to the chosen troops of the northern army.

At the commencement of the revolution, Colonel Burr, then about eighteen years of age, at the first sound of the trump of war (as if bred in the camp of the great Frederick, whose maxim was "to hold his army always in readiness to break a lance with, or throw a dart against, any assailant"), quit his professional studies, and rushed to the camp of General Washington, at Cambridge, as a volunteer from which he went with Colonel Arnold on his daring enterprise against Quebec, through the wilds of Canada (which vied with Hannibal's march over the Alps), during which toilsome and hazardous march he attracted the attention and admiration of his commander so much, that he (Arnold) sent him alone to meet and hurry down General Montgomery's army from Montreal to his assistance; and recommended him to that general, who appointed him an aid-de-camp, in which capacity he acted during the winter, till the fatal assault on Quebec, in which that gallant general, his aid McPherson, and Captain Cheeseman, commanding the forlorn hope, fell. He afterwards continued as aid to Arnold, the survivor in command.

Here I must begin to draw some of the outlines of his genius and valour, which, like those of the British immortal, Wolf, who, at the age of twenty-four, and only major of the 20th regiment, serving on the continent, gave such specimens of genius and talents as to evince his being destined for command.

At the perilous moment of Montgomery's death, when dismay and consternation universally prevailed, and the column halted, he animated the troops, and made many efforts to lead them on; and stimulated them to enter the lower town; and might have succeeded, but for the positive orders of Colonel Donald Campbell, the commanding officer, for the troops to retreat. Had his plan been carried into effect, it might have saved Arnold's division from capture, which had, after our retreat, to contend with all the British force instead of a part. On this occasion I commanded the first company in the first New-York regiment, at the head of Montgomery's column, so that I speak from ocular demonstration.

The next campaign, 1776, Colonel Burr was appointed aid-de-camp to Major-general Putnam, second in command under General Washington at New-York; and from my knowledge of that general's qualities and the colonel's, I am very certain that the latter directed all the movements and operations of the former.

In January, 1777, the continental establishment for the war commenced. Then Colonel Burr was appointed by General Washington a lieutenant-colonel in Malcolm's regiment, in which he continued to serve until April, 1779, when the ill state of his health obliged him to retire from active service, to the regret of General McDOUGALL, commanding the department, and that of the commander-in-chief, who offered to give him a furlough for any length of time, and to get permission from the British general in New-York for him to go to Bermuda for his health. This item will show his value in the estimation of Generals Washington and McDOUGALL.

During the campaign of 1777, Malcolm's regiment was with the main army, and commanded by Lieutenant-colonel Burr. For discipline, order, and system, it was not surpassed by any in the service; and could his (the lieutenant-colonel's) and Wolfe's orderly-books be produced, they would be very similar in point of military policy and instructions, and fit models for all regiments.

This regiment was also but led at the Valley Forge in 1777 and winter of 1778, under General Washington, and composed part of his army at the battle of Monmouth on the 28th of June, 1778, and continued with it till the close of the campaign of that year, at which time it was placed in garrison at West Point by General Gates; but, upon General McDOUGALL's assuming the command of the posts in the highlands in December, Malcolm's, Spencer's, and Patten's regiments were together ordered to Haverstraw. The three colonels were permitted to go home for the winter on furlough, and Lieutenant-colonel Burr had the command of the whole brigade, at a very important advanced post.

At this period General McDOUGALL ordered a detachment of about three hundred troops, under the command of Lieutenant-colonel Littlefield, of the Massachusetts line, to guard the lines in Westchester county, then extending from Tarrytown to White Plains, and from thence to Mamaroneck or Sawpits, which last extension was guarded by Connecticut troops from Major-general Putnam's division.

In this situation of affairs a very singular occurrence presented, viz., that neither Lieutenant-colonel Littlefield, nor any other of his grade, in the two entire brigades of Massachusetts troops composing the garrison of West Point, from which the lines were to be relieved, was competent, in the general's estimation, to give security to the army above and the lines of those below; and, in consequence, he was compelled to call Colonel Burr from his station at Haverstraw to the more important command of the lines in Westchester, in which measure, unprecedented as it was, the officers acquiesced without a murmur, from a conviction of its expediency. At this time I was doing the duty of adjutant-general to General McDougall.