Colonel William Stokes, in command of the Fifth Tennessee cavalry, surprised a party of rebel guerrillas under Champ Ferguson, at a point near Manchester, Tenn., and after a severe fight routed them, compelling them to  leave behind twenty-one in killed and wounded.--this morning, at a little before three o'clock, an attempt was made on Seabrook Island by a large force of rebels, who came down the Chickhassee River in boats. They approached in two large flats, filled with men, evidently sent forward to reconnoitre, with a numerous reserve force further back, to cooperate in case any points were found to be exposed. One of the boats came down to the mouth of Skull Creek, where they attacked a picket-boat containing a corporal and four men of the Seventy-sixth Pennsylvania. They first fired three shots and then a whole volley, and succeeded in capturing the boat and those in it, after a severe hand-to-hand fight. Whether there were any casualties could not be ascertained. Further on, meeting an unexpected resistance, they retreated.
Lieutenant-General Grant formally assumed the command of the armies of the United States to-day. The following was his order on the subject: