Department of Southeast Virginia and Fort Monroe, compiled in the Bureau of Topographical Engineers of the War Department, scale 1/200 000-inch. The Bureau also kindly furnished others for reference, viz: Part of the map of the Military Department of Southeast Virginia and Fort Monroe, showing the approaches to Richmond and Petersburg, scale 1/80 000-inch, and Numbers 1, 2, and 3 of the Peninsular Campaign maps, together with the Henrico County map, the former engraved, and the two latter photographed for the use of the armies operating against Richmond. The detailed map of Northeast Virginia and vicinity of Washington, scale 1 inch to the mile, compiled under the direction of Major A. W. Whipple, U. S. Topographical Engineers, was also placed at the disposal of this department.

At different intervals during the several months previous to the opening of the spring campaign a great many reconnaissances and surveys had been pushed as far as the different fords of the Rapidan and that section of the country had become accurately known. The movements of the army in November and December, 1863, between the Rapidan and Mine Run, had also furnished some very important information which subsequently proved of great value. Beyond the latter narrow strip of local knowledge along the Rapidan, the experience gained in the memorable campaign of the Army of the potomac during the months of may and June of 1864 showed very conclusively that however well the only accessible maps might have served the purposes of general knowledge, still they furnish but little of that detailed information so necessary in selecting and ordering the different routes of marching columns, and were too decidedly deficient in accuracy and detail to enable a general to maneuver with certainly his troops in the face of a brave and everwatchful enemy. This was more especially the case as the country in itself proved to be of the worst and most impracticable character-a most difficult one for executing any combined movement. This may appear strange to those who reflect that the Commonwealth of Virginia is among the oldest of the States of the Union. They necessarily conclude that her archives should contain the most perfect geographical and topographical material for mapping her extensive domains. The proof that such has not been the case, and that his great want has been felt by her own military officers, is shown by the large surveying parties kept by them constantly in the field. Some of the results of their labors have lately fallen into my hands, a few excellent maps having been captured which bear evidence of very recent construction. On the face of them not only appear their familiar names, but the distinguishing peculiarities of workmanship of assistants employed on different Government surveys at the very commencement of the war. Although the enemy has no doubt suffered at times from want of accurate maps, still he at all times possessed a superior knowledge of the country, and could always obtain reliable guides from among its inhabitants, thus affording him a very great advantage over his adversary. In order to be able to cope with him with anything like equal advantage it soon became apparent that the difficulties to which reference has been made would not only have to be overcome by gathering material with the onward march of the army, but that the desired information would have to be obtained in anticipation of any move. To accomplish this the officers and assistants of my party were kept constantly occupied both day and night; they were not only called upon to prepare the much needed maps with the detailed corrections,