Our dispatches from the new seat of war, this morning, are exciting in the highest degree. They may be summed up briefly as follows: The rebels have captured the city of York, the most important point on the railroad from Harrisburg to Baltimore, and are advancing towards Lancaster. Many bridges across the Susquehanna have been burned.
Havre de Grace is seriously threatened. Its capture would cut off all railroad communication with Washington.
The attack on Harrisburg has begun, and is still progressing.
Gen. Hooker is removed from command, and succeeded by Gen. Meade, an almost untried officer. The rebels declare that Pennsylvania is to be the battle ground in future.
There is nothing of special importance from the south. A movement from Johnston is expected soon, but his intentions are not known.