The Photographic History of The Civil War: in ten volumes, Thousands of Scenes Photographed 1861-65, with Text by many Special Authorities, Volume 8: Soldier Life and Secret Service.
Francis Trevelyan Miller, Ed.

Again, after Antietam, what tremendous tales of Southern strength must have held McClellan an entire month along the north bank of the Potomac, while Stuart, with less than two thousand troopers, rode jauntily round about him unscathed. It was not until well along in 1863, when the Federals began to wake up to the use of cavalry, that fairy tales gave way to facts, and Hooker and Meade could estimate the actual force to be encountered, so that by the time Grant came to the Army of the Potomac in 1864, he well knew that whatsoever advantage Lee might have in fighting on his own ground, and along interior lines, and with the most devoted and brilliantly led army at his back, the Union legions far outnumbered him. Then, with Grant's grim, invincible determination, there were no more footsteps backward.

Yet even Grant had very much to contend with in this very matter. Southern families abounded in Washington; Southern messengers of both sexes rode the Maryland lanes to Port Tobacco; Southern skiffs ferried Southern missives in the black hours of midnight under the very muzzles of the anchored guns in the broad reaches of the Potomac; Virginia farm boys, or girls—born riders all—bore all manner of messages from river to river and so to the Southern lines southeast of Fredericksburg, and thus around to Gordonsville and the Confederate army.

The Northern newspapers, under the inspiration of professional rivalry, kept the Southern cabinet remarkably well informed of everything going on within the Union lines, and not infrequently prepared the Confederate generals for the next move of the Union army. It was this that finally led the vehement Sherman to seek to eliminate the newspaper men from his military bailiwick, about as hopeless a task as the very worst assigned to Hercules. Grant, with his accustomed stoicism, accepted their presence in his army as something inseparable from American methods of warfare, adding to the problems and perplexities of the generals commanding,