However, delays in fitting out the schooner prevented her from taking part in the Port Royal operation and caused her to be reassigned twice before her active service began: first to Flag Officer William W. McKeon's Gulf Blockading Squadron and then, on 2 December 1861, to the Mortar Flotilla established under Commander David Dixon Porter to support Farragut's forthcoming campaign against New Orleans, Louisiana, and the lower Mississippi River.

For the next month, while Farragut labored to get his deep-draft, saltwater warships into the Mississippi River, Porter kept his vessels busy preparing to support the flag officer's thrust upstream.

Originally, similar operations against Mobile, Alabama, were next on the mortar flotilla's agenda; and Adolph Hugel and her sisters dropped downriver and returned to the Gulf of Mexico to await Farragut who was to join them in attacking that port.

Meanwhile, however, new orders from Washington sent Farragut back upstream to join Flag Officer Charles Henry Davis' Western Flotilla which had been fighting down the Mississippi River from Cairo, Illinois.

When these instructions reached the flag officer, he had just returned to New Orleans from Vicksburg, Mississippi, where he had found Confederate cannon which could shell his ships with near impunity, because their location high on the cliffs kept them out of the field of fire of the Union Navy's low trajectory guns.

Hugel found herself and her sisters just below the Confederate river fortress; and, on the 28th, they shelled the hillside batteries as Farragut's salt water men-of-war ran the gauntlet.

As a result, in compliance with an Army request, Secretary of the Navy, Gideon Welles, called 12 of Porter's schooners back to the east coast for duty on the vital Virginia river.

Adolph Hugel – one of the mortar boats brought back to the Atlantic Ocean coast – reached Hampton Roads on 31 July.

Lee's army had routed General John Pope's troops in the Second Battle of Bull Run, had invaded Maryland, and was a threat to the Federal capital.

During Confederate General Jubal Early's Washington raid in July 1864, the Military Governor of Alexandria requested Adolph Hugel's help in defending his city in the event of an attack.