The Situation in Florida.
--A letter to the Savannah Republican, dated near Jacksonville, Fla., the 8th inst., says:‘ All is quiet to day at the front. We are daily, yes hourly, expecting an engagement. We have the enemy now inside of the Three Mile Branch. They occupy from there to Jacksonville. Their forces are variously estimated at from 15,000 to 25,000. Gen. Gillmore is in command. In the several engagements we have driven them from every position they have taken up to their present strong hold. We have not yet attacked them there.
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