John Haggan was born in Belfast, Co Down, Ireland (modern-day Northern Ireland) on 11 April 1877. He was the son of Edward Haggan (1856-1928) and Mary Magee (1858-1929) who had been married in Belfast in 1876.
John's siblings were Robert (b. 1876), Agnes (b. 1879), James (b. 1885), Sarah (b. 1886), Eliza Jane (b. 1888), Edward (b. 1887), Thomas (b. 1890), Samuel (b. 1891) and Mary Ann (b. 1893) and Alexander (b. 1894).
In the late-1890s John joined the Royal Horse Artillery and served during the Boer War. In 1901 he was part of the procession at Queen Victoria's Funeral.
John does not appear on the 1901 census of Ireland. On the 1911 census he is living at 53 Thorndyke Street, Pottinger, Castlereagh, East Belfast, the home of his younger brother James and his family and it is indicated that he is literate and comes from a Presbyterian background. His profession is listed as shipyard labourer and he is unmarried.
John initially signed-on to the Titanic in Belfast for the delivery trip to Southampton. When he signed-on again, in Southampton, on 6 April 1912 he gave his address as the Sailors' Home, Southampton. His last ship had been the Braehead and as a fireman he received monthly wages of £6.
Haggan survived the sinking, possibly on boat 3.
John Haggan returned to England on the Lapland shortly after the Carpathia arrived in New York City.
John, who did not like to discuss the Titanic disaster, continued to live in Belfast, surrounded by his extended family. He never married and later lived at 49 Thorndyke Street, East Belfast. He died in the Royal Victoria Hospital on 13 January 1952, aged 74. He was buried in a family plot (C4-670/C4-671) with his parents and several of his siblings in Dundonald Cemetery, Dundonald, Co Down.