...d passed the mouth of Warsaw Sound, and learned that Commandant Drayton had left his anchorage there with the Monitor Passaic, and had joined and taken command as senior officer of the whole fleet in Ossabaw Sound , preparatory to a joint attack on Fort McAllister, located a few miles up the Ogeechee River. He had left the gunboat Marblehead, Captain Robert Scott, there, to blockade this outlet from Savannah....