was in the York River when the United States declared war on Germany on 6 April, entering World War I. After fitting out at Brooklyn Navy Yard, she got underway from New York on 15 May with , , , and , and joined convoy at Halifax, Nova Scotia, en route to Ireland. Upon arrival at Queenstown on 24 May, O'Brien was assigned to the 6th Destroyer Division which cooperated with the British forces. She patrolled off the Irish coast in company with other destroyers answering distress calls and meeting eastbound convoys to escort them through the war zone. While escorting SS Elysia off Queenstown on 16 June, lookouts on O'Brien sighted a periscope. Heading toward the submarine for an attack, a lookout in the foretop saw the submerged boat pass close along the starboard side. A depth charge was dropped but no immediate evidence of damage was found. Nearly three hours later, the British vessel reported a large patch of oil in approximately the same position. The next morning, Cushing also reported and confirmed Jessamines report. The British Admiralty believed the submarine was probably seriously damaged. However, later investigation reveals that German submarine , the submarine in question, continued to operate and completed her cruise. In the summer of 1918, O'Brien was transferred to the French coast where she continued her antisubmarine patrols through the end of the war. Inter-war period After the signing of the Armistice on 11 November, which ended all fighting, O'Brien transported mail and passengers between Brest, France, and Plymouth, England. She returned to New York on 8 January 1919, but returned to European waters in May when she served as one of the rescue pickets stationed along the route across the Atlantic flown by three Navy NC-type seaplanes in the first aerial crossing of the Atlantic. In 1919, she assisted in the unsuccessful first attempt to lay the Ambrose Channel pilot cable. In July 1920, she was assigned the hull code of DD-51 under the US Navy's alphanumeric classification system. O'Brien was decommissioned at Philadelphia on 5 June 1922. The ship was struck from the Naval Vessel Register on 8 March 1935, and broken up at the Philadelphia Navy Yard, and her materials sold for scrap on 23 April. The ship's bell remains in the Plattsburgh Memorial Chapel on the former Plattsburgh Air Force Base. Notes References Bibliography External links O'Brien-class destroyers Ships built