Hello, I believe John Hunter Gowan lived at what is known as Mount Nebo, (name then changed to Mount St. Benedict later) in Hollyfort, Gorey, Co. Wexford.
He was a justice of the peace, and captain of the yeomanry during 1798. His house was burned by the rebels in 1798. There is numerous articles and pictures in the book Historic Gorey 4 - Reflections of 1798 by Michael Fitzpatrick. JHG died in 1824 aged 97 and is buried in Hollyfort Graveyard in the family vault. He is infamous for his involvement in the rebellion of 1798.
John Gowan Senior, born 1699 married Anne/Mary the daughter of Rev Henry Hatton, Gorey. Their first born son was Henry Hatton Gowan and the above John Hunter Gowan was his brother. p142 of Historic Gorey 4.
On page 120 of the book: Major Thomas Fleming, Royal Artillery who fought at the battle of Arklow in 1798, married Elizabeth Gowan 4th child and 4th daughter of John Hunter Gowan, married Major Thomas Fleming c1795.
Further articles on page 144, 145, 146 and p147 of Historic Gorey 4.
p147 gives information on the last will and testament of JHG who died 24/5/1824 and lists the children etc.
Also Gowan-Hastings Family in Canada.
Hope this helps!
Gerard