USS Iris steamed with Nipsic to the North Edisto River 8 February 1864 to support a reconnaissance in force undertaken by the Union Army as a diversion to prevent Southern troops in the Charleston area from moving to Florida for action against Brigadier General Truman Seymour.

On 12 December Iris moved to the Savannah River to be on hand to support General William Tecumseh Sherman at the end of his march through Georgia to the sea where he was assured of supplies and a secure operating base behind the big guns of the Navy.

Iris returned to service early in February in time to participate in the expedition to Bull's Bay which diverted Confederate troops from General Sherman's path as he marched north close to the sea ever ready to retire to the coast under Naval protection if necessary.

This diversionary movement was one of the factors which compelled the Confederacy to evacuate Charleston, South Carolina, where the war had begun four long years earlier, with the firing on Fort Sumter.

Upon learning of Davis' capture at Irwinville, Georgia, she returned to Charleston where she remained until sailing north with Rear Admiral John A. Dahlgren in Pawnee 17 June.