Ferguson settled in Dublin, where he practiced law. In 1846, he toured European museums, libraries and
archaeological sites with strong connections to Irish scholarship. He married
Mary Guinness (1823–1905) in 1848, a great-great-niece of
Arthur Guinness, and the eldest daughter of
Robert Rundell Guinness who founded the
Guinness Mahon bank. At that time he was defending the
Young Irelander poet
Richard Dalton Williams. He retired from the bar in 1867 when he was appointed First Deputy Keeper of
Public Records of Ireland. As well as his poetry, Ferguson contributed a number of articles on topics of Irish interest to antiquarian journals. In 1863, he traveled in
Brittany, Ireland,
Wales, England and
Scotland to study
megaliths and other archaeological sites. His collected poems,
Lays of the Western Gael was published in November 1864, resulting in the award of a
degree LL.D. honoris causa from Trinity. He wrote many of his poems with both Irish and English translations. He received a knighthood in 1878. an organisation dedicated to the advancement of science, literature and antiquarian studies. His house in
North Great George's Street, Dublin, was open to everyone interested in art, literature or music. He died in
Howth, just outside Dublin city, and was buried in
Donegore near Templepatrick,
County Antrim. ==Works==