Pinkerton, John (1845–1908), tenant farmer, magistrate, and MP, was the son of John Pinkerton of Seacon, near Ballymoney, north Antrim, and his wife Nancy (née Pinkerton). John Pinkerton senior was a unitarian tenant farmer and linen merchant who died young after falling from his horse. With help from relatives, Nancy Pinkerton managed to retain the tenancy, but her difficulties may have contributed to her son's radical views on the land question. There was an older sister. Locally educated by Rev. J. M. McFadden, a unitarian minister, John junior worked on the family farm and became involved in tenant farmer organisations. Between 1880 and 1885 he was an active participant in the Route Tenants Defence Association (north Antrim) and was connected with the Antrim Central Tenant Right Association. During the land war he was involved with the Ballycastle and Loughguile Land League branches. He was also a lukewarm supporter in the early 1880s of the Liberals, but saw their land policies as too conservative.
In 1885 Pinkerton became a magistrate and took the plunge into political life, unsuccessfully contesting the north Antrim seat in the general election as an independent farmers’ candidate. With the defeat of Gladstone's first home rule bill in 1886 and the subsequent general election, Pinkerton again ran for parliament, this time hand picked by Charles Stewart Parnell (qv) for Galway city. Although an Ulster unitarian, he supported a federal scheme of home rule, and in May 1886 was involved in the foundation of the Irish Protestant Home Rule Association in Belfast. He was chosen for Galway city in part because of a need to infuse the Irish parliamentary party with more protestants and help undermine the assumed protestant-unionist and catholic-nationalist political formula. Unopposed, Pinkerton held the seat until 1900.
For the next few years Pinkerton worked hard to promote protestant support for home rule in England and Scotland, as well as in Ulster. As a backbencher at Westminster, he was one of the few tenant farmers in the Irish party, and often spoke on issues that touched the land question. He also tended to raise matters concerning his native north Antrim, sometimes at the expense of his Galway constituency. With the Irish party split in 1890–91, Pinkerton became an anti-Parnellite, winning his Galway seat again on that platform. In the 1895 election he campaigned on his devotion to the land question and his protestant nationalism. The next five years were not an easy time for him; restrictions on financial support from the Irish party meant he had to spend more time at his Ulster farm and less in parliament. With the reunification of the Irish party in 1900 and the consequent change in local candidate selection, Pinkerton was not chosen at the Galway city convention that year, and returned to his farm, which he had purchased under the 1885 Ashbourne Land Act. He died 4 November 1908. In 1874 he had married Isabella Pinkerton, his first cousin, and they had one son and one daughter. Another daughter died in infancy. His papers are in PRONI.