As America entered World War I,
Patterson patrolled along the New England Coast in the approaches to Newport and Boston to safeguard inbound trans-Atlantic convoys. One patrol mission took her as far north as
St. John's, Newfoundland. The first United States help to the hard-pressed allies was the assignment of US destroyers to the
British Fleet to help combat enemy
submarines that threatened to cut the sea lifelines to the
British Isles.
Patterson was the
flagship of the second division of destroyers to cross the Atlantic on this mission. But the destroyers could not make it across the North Atlantic without refueling. Newly commissioned fleet oiler , whose executive officer and chief engineer was
Lieutenant Chester W. Nimitz, stationed herself in mid-Atlantic, between Boston and
Queenstown,
Ireland.
Patterson led Division 5 out of Boston Harbor on 21 May 1917 and made rendezvous with
Maumee the morning of 28 May. She was the first destroyer to maneuver alongside
Maumee to receive fuel oil enabling her to complete the Atlantic crossing. The division arrived Queenstown, Ireland, on 1 June 1917. There
Patterson and her sister destroyers received British signal books and
depth charges.
Patterson began patrol and escort in the approaches to Queenstown on 5 June. On 12 June, she dropped depth charges to help drive away a German
U-boat attacking SS
Indian. A collision with His Majesty's tug
Dreadful at the entrance to
Berehaven Harbour, Ireland, the night of 1 January 1918, damaged ''Patterson's
bow but she resumed regular escort and patrol on 5 February. Two days later she rescued 12 survivors of steamship Mexico City
, torpedoed by a German submarine. Patterson'', patrolling in the
Irish Sea on 17 May, dropped depth charges that drove away German . She continued patrol out of Queenstown until 4 June, then departed for the United States. On 16 June, one day out of
Bermuda,
Patterson rescued survivors of the
Norwegian bark Kringsjaa, sunk by the German submarine . She landed the survivors at the
Cape May Naval Station and continued on to the
Philadelphia Navy Yard at Philadelphia, arriving on 18 June for overhaul. She departed
Norfolk,
Virginia, on 17 August 1918 for
Tompkinsville,
New York. There she joined the escort of the
battleship bound for Norfolk. On 22 August 1918, she got underway from Norfolk as
flagship of the “
Patterson Group”, a special hunting squadron that included 11
submarine chasers. The
Patterson Group hunted German
U-boats north from the
Virginia Capes to New York. During the predawn hours of 27 August 1918, the American armed
cargo ship SS Felix Taussig mistook the Patterson Group submarine chaser for a German submarine in the
Atlantic Ocean south of
Long Island, New York, and opened gunfire on
SC-209, hitting her with two
shells.
SC-209 caught fire and sank in only three minutes at with the loss of two
officers and 16
men. The submarine chaser rescued
SC–209′s five survivors, four of whom were wounded.
Patterson and two other submarine chasers searched the area but found no more survivors.
Felix Taussig stood by to render assistance until
Patterson directed her to continue her voyage to New York City. It was the U.S. Navy's largest loss of life in a single
friendly fire incident during World War I.
Patterson carried the wounded survivors into
New York Harbor for transfer to the U.S. Navy
hospital ship .
Patterson dropped
depth charges to drive away a German U-boat on 3 September 1918, continuing
antisubmarine warfare patrols along the
United States East Coast until the special hunting group disbanded on 23 November 1918, twelve days after the
armistice with Germany brought World War I to an end. ==Inter-war period==