There are some circumstantial 'reasons' why Samuel may have belonged to Islandmagee. The clan there spelled their name with an 'o' ending, McIlhaggo, as did Samuel on occasions. Second, the first name Samuel was certainly favoured among the McIlhaggos there and some of our information comes from the Will of Samuel McIlhaggo who died in 1818. This Will makes it clear that he had a son and three grandsons, two of whom were named Samuel and John. Perhaps it is not a coincidence that Samuel born in 1832 had sons named Samuel and John, though they cannot have been the two referred to in the Will. The dates don't fit. We are probably looking at two generation apart. It is therefore possible that the Samuel named in the Will, or one of his brothers, (the great-grandsons of the Samuel who made the Will), could have been the father of Samuel born in 1832. Third, the clan families on Islandmagee were all farmers, so if Samuel born in 1832 in his early days was a cattle drover/dealer, then this was something he had likely been brought up to. Fourth, whether or not he was son of the brother called Samuel, it could have been that Samuel who was the witness named at the baptism of a couple of the children of Samuel and Elizabeth.
Do we have any further clues from later events? Not very much. We think that two children of Samuel and Elizabeth must have died as infants. If any of the others survived and married I'm afraid I haven't found any such records. We do have the evidence of the 1901 and the 1911 Irish Censuses. Samuel senior would have been 69 in 1901 but there is no Samuel of that age in the Census. Samuel junior would have been 30, and again, there is no Samuel of or near that age. Nor do they appear in the 1911 Census. John however would have been 26 in 1901 and in that Census there is a 26 year old John and his 25 years old wife Mary living at 102 Queen Street, Ballymena. He was a Carter. In the 1911 Census there is no equivalent Mary though there is a 36 year old John who is boarding with a Sinclair family at 32 Agnes Street, Belfast. He was a Shipwright. He was recorded as single, though he may have preferred to say he was single rather than a widower, if Mary had died.