(Hayes Collection, SHC) Later the Virginia Dare was purchased by the Union Navy on 14 October 1861, and renamed USS Delaware.

Delaware took part in the capture of Roanoke Island from 7 to 8 February 1862, securing the landing of Union infantry on the island by shelling an awaiting enemy detachment at Ashby's Harbor;[3] and on 10 February 1862 she took part in the attack on Elizabeth City, North Carolina, where she shared in the capture or destruction of five Confederate gunboats and two schooners.

It was during this foray that she was nearly ambushed at the town wharf by a force of Confederate soldiers and artillery hiding among the brush near the dock.

Union commander Rush Hawkins, who was in the yardarm of the foremast, spotted the Confederates and warned the helmsman in time to sheer off.

Delaware's superstructure was severely shot up by rifle fire, but fortunately the artillery overshot its mark.

Until 5 April 1863, Delaware cruised in the James and York Rivers and Chesapeake Bay, then on the North Carolina coast until 27 November 1863, when she sailed to Baltimore, Maryland, for repairs.

On 27 March 1864, she returned to the waters of Virginia, to patrol and perform picket duty, transport men and ordnance stores, and clear the rivers of torpedoes (mines) until the end of the war.

While operating near Indian Key, Florida on 20 June 1897, she seized the tug Dauntless bound for Cuba that was carrying 175 rifles, 300,000 rounds of ammunition, medical supplies and 27 men on board in violation of U.S. neutrality laws.

Secretary of the Treasury Lyman J. Gage singled out Louis McLane in his 1897 report to congress for her enforcement action.