From East Tennessee.
Greenville, Feb. 26.
--For reasons which it would be imprudent to disclose at present Gen. Longstreet has withdrawn his forces to--. The movement was made quietly, and without interruption from the enemy, who has not crossed the Holston as yet.
Major-General Buckner has been assigned to the command of Hood's division.
Major-General Ransom takes command of all the cavalry in this department.