Another pressure on McClellan
--By a Washington letter, of February 20th, we learn the following:‘ Washington city is filled with rumors respecting the disposition of the rebels to evacuate Manassas. It is said that the trains are busily in motion sending troops not only down to Richmond, but farther south to a point in North Carolina, where it is supposed General Burnside intends to strike. If this evacuation is taking place it will necessarily be slow work. It is estimated here that with the utmost activity on the part of the rebels they cannot transport their army and stores to Richmond in less than three weeks, and even then much of their bulkiest baggage would necessarily be lost. A pressure has been brought to bear upon General McClellan to advance immediately, if for another purpose than to assure himself that the rebels are not really fleeing away. It is felt that he cannot afford to have the same accident happen to him that occurred to Gen. Buell at Bowling Green.
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