The surname HAWTHORNE is locative in origin, that is, it refers to a place or a feature of the landscape where the original bearer lived or owned land. In this case the feature is a Hawthorn (from Old English haguthorn), or the place name in Co. Durham. The earliest record of the surname is in England; William de Hagethorn is listed in the Feodarium Prioratus Dunelmensis in 1155. Henry atte Hauthorn appears in the Subsidy Rolls for Worcestershire in 1327. The Hawthornes were well established in Galloway as propietors of Meikle or Over Aires in the parish of Kirkinner. They first appear in the parish records in 1455 as the Chamberlain accounts "for 15 balls farinae avenaticae" (oatmeal) of the escheat of Daude Halthorn. The family became kindlie tenants on the lands of Airies under the Church, and "Sir" Mychaell Hathorne was reader in toskertoun in the first list of reformed clergy. The name was first introduced to Ireland from Scotland during the Ulster Plantation of the early seventeenth centuary. Although not sufficiently established to be counted as "Principal names" in the census of 1659, there were undoubtedly settlers of that name already present. In the census of 1890, twenty seven families of the name are recorded in Ireland, 23 of these in Ulster, where they were and still are mainly to be found in Antrim, Down and Armagh.
The above is a quotation is from a lovely picture, which was a gift to me from my son.