The third candidate falls in the middle. He is John who married Mary Houston in about 1832, and so may have been born at the end of the first decade of the century. John and Mary had children in 1833 (Eliza) and 1834 (William). Unless some more telling evidence comes our way the three Johns we have noted appear to represent three generations of the clan farmers in Maxwellswalls. Although at the moment we don't know where to place them, we may add an interesting note about John and Eliza. They appear, with the surname McIlhagge in the 1911 Irish Census at 32 Maxwellswalls, the only Maxwellswalls folk left. John was 86 and Eliza was 70, therefore being born respectively in 1825 and 1841. It could be that John died that year for the following year, 1912, Eliza from Maxwellswalls signed the Ulster Covenant and there is no 'John' signature.
So do we know anything about John who married Mary Houston and their family? Eliza could be the clan member who married Mathew McDowell on 17th May 1856 at Ballymena 3rd Presbyterian Church. Rather less likely she could have been Elizabeth who married James Graham on 10th April 1854 at Ballymena Registrar's Office, Kirkinriola. William may have married Catherine Johnstone Easton and had a daughter called after William's mother, Mary Houston McIlhagga, born 23rd April 1870. They also had four other children, John (b. 15th Nov. 1863), Catherine Johnston (b. 10th Oct 1865), William (b. 29th Mar 1868) and Robert Easton (b. 12th May 1872). We have to add an interesting conjecture about Mary Houston. Her marriage to John produced two children, Eliza and William in 1833 and 1834 and we don't know of any further children. However there are further children for a Mary Houston and a William Gage McIlhaggie, all in subsequent years, Rebecca (b. 1835), Samuel (b. 1844), Henry and Margaret who gave notice of William's death on 12th October 1865. What we may surmise therefore is that John died in 1834/5 and Mary remarried, probably his brother, William Gage. This is how I am presenting this situation in the Maxwellswalls Tree Construction, unless anyone knows better!