CAMDEN STATION, July 14, 1864. (Received 6. 40 p. m.)

Honorable E. M. STANTON,

Secretary of War:

I received your communication by Mr. W. at 8 this morning. We forwarded a construction train with 100 guards promptly to Monocacy to reopen the road. I sent a special messenger on this train to get through to General H. with all possible dispatch, suggesting that the route through Williamsburg and Martinsburg would probably prove the best. I am just advised that the train has got through without difficulty, and we are now in communication by telegraph, and the track is in order to Monocacy. Operator reports that between 2,000 and 3,000 cavalry, with some artillery, of General Howe's forces, are in that vicinity, and it is stated that communication is open by railroad to Sandy Hook. On consultation with Colonel Chipman, I send a duplicate of the cipher telegram received from General Halleck to Monocacy, instructing the messenger who has your dispatch to take General H. 's also. Ascertaining that we could forward by telegraph, via Philadelphia and Pittsburg and Wheeling, to Cumberland, I sent at 3 this morning the following dispatch to General Kelley:

General B. F. KELLEY,

Cumberland, Md.:

Our Washington branch is again open, and the entire forces of the enemy, have retreated rapidly from the vicinity of Washington toward Edwards Ferry, vigorously pursued by General Wright. The Department is very anxious to ascertain the position of General Hunter. Can you not advise the Secretary fully? Cannot General Sullivan push on to Harper's Ferry? The telegraph line and road should be opened promptly to that point. I am satisfied energetic action will be specially appreciated. Are you in communication with General Howe? Can he cover the road to Monocacy? We expect to reopen from Baltimore to Monocacy this day.

J. W. GARRETT,

President.

I trust this will elicit for your direct the desired information. Colonel Chipman has started on a special train, and I expect will reach Monocacy by 9 a. m. I hope to make a further report in a short time of the situation at Harper's Ferry.

J. W. GARRETT,

President Baltimore and Ohio Railroad.

BALTIMORE, July 14, 1864. (Received 7. 30 p. m.)

Major-General HALLECK,

Chief of Staff:

A special train awaited Colonel Chipman on his arrival, and, having advices of the road being clear to Monocacy, he started at 6 p. m. I have telegraphed the officer in command at Monocacy to arrange all possible facilities, and have furnished him with an order to our agent at Martinsburg for a special train should he desire it on his arrival at that point. Your cipher telegram was duplicate to Monocacy and placed in charge of the same courier who goes forward with the dispatch of the 12th instant of the Secretary of War to General H. I have also directed that a duplicate of your telegram be sent via Sandy Hook with the hope that it may possibly get through by that route more rapidly. Our men are taking it up by hand-car, having full and careful instructions.

J. W. GARRETT,

President.