Telegram To General G. B. Mcclellan.

War Department, Washington, D. C., June 18, 1862.

MAJOR-GENERAL McCLELLAN:

Yours of to-day, making it probable that Jackson has been reinforced by about 10,000 from Richmond, is corroborated by a despatch from General King at Fredericksburg, saying a Frenchman, just arrived from Richmond by way of Gordonsville, met 10,000 to 15,000 passing through the latter place to join Jackson.

If this is true, it is as good as a reinforcement to you of an equal force. I could better dispose of things if I could know about what day you can attack Richmond, and would be glad to be informed, if you think you can inform me with safety.

A. LINCOLN.