HEADQUARTERS ARMY OF THE POTOMAC,
Camp Lincoln, near Richmond, June 26, 1862.

GENERAL: I have the honor to report the following information relative to the forces and defenses of the rebel army of the Peninsula, including the forces and defenses of Yorktown up to the time of the evacuation and of Richmond and vicinity up to date of this report; this information having been obtained and extracted from statements made at these headquarters by spies, contrabands, deserters, refugees, and prisoners of war, in the order of time as hereinafter indicated, and which at the time of reception were made the subject of special reports to you. I have also appended to this report a varied summary of those forces and defenses, showing by different combinations about the probable number of these forces and the locality and strength of their defenses.

The summary of the general estimates of the rebel army at Yorktown up to about the time of the evacuation shows their forces to be 100,000 to 120,000. The specific information regarding the rebel army at Yorktown, obtained to date, shows the following-named organizations: Twenty-two brigades, ninety-one regiments, three legions, two battalions infantry, five battalions artillery, sixteen companies artillery, and two companies infantry.

This information is necessarily limited, because the rapid accumulation of rebel troops at Yorktown and their subsequent changes of organization rendered it impossible to obtain but a partial specific knowledge of their forces.

The summary of general estimates of the rebel army shows their forces to be at this time over 180,000 men, and the specific information already obtained warrants the belief that this number is probably considerably short of the real strength of their army, which is as follows: Two hundred regiments infantry and cavalry, including the re-enforcements just arrived of Jackson's and Ewell's forces (eight battalions), five battalions artillery, twelve companies infantry and independent cavalry, and forty-six companies of artillery-in all about forty of fifty brigades. The forces under General Jackson just arrived have been ascertain by general estimate and by partial specific information, and the number is probably about 30,000, which includes about 100,000 sent from Richmond to re-enforce him lately, and which only reached him and formed a junction at a very recent date.

The summary shows the number of earthworks completed by the rebels in the vicinity of and for the defense of Richmond to be fifty-two, and the specific number of guns shown to be mounted on thirty-six of the same is about 205, leaving sixteen fortifications without specific information as to the number of guns.

All of which, general, is respectfully submitted, by your obedient servant,

E. J. ALLEN.

Major General GEORGE B. McCLELLAN,

Commanding Army of the Potomac.

HEADQUARTERS ARMY OF THE POTOMAC,
Camp at Harrison's Landing, Va., August 14, 1862.

GENERAL: I have the honor to report the following information of the forces and defenses and the movement of the forces of the rebel army of Richmond and vicinity from the time of commencing the