Early in the American Civil War, when tensions between Britain and the United States where raised as a result of the Trent Affair of November 1861, Ardagh was sent to the colony of New Brunswick to construct a military telegraph line to the St. Lawrence river. He embarked on the transport ship Victoria at Queenstown, Ireland on 26 December 1861, but the ship was driven back to the port by storms. She sailed again on 13 February 1862, but was only saved from foundering by the exertions of Ardagh and his troops, which enabled her to reach Plymouth on 12 March. Ardagh's conduct was highly commended by the Commander-in-Chief, the Duke of Cambridge.
