William Henry Marsh Parr was born in Hindley Green, Lancashire, England over the closing months of 1882.
He was the son of John Turner Parr (1854-1913) and Hannah Marsh (1849-1922), both Lancashire natives. His father, an office caretaker, was married to Hannah Marsh in Manchester in 1881 and William became one of five children, three of whom survived infancy. His surviving siblings were: Hannah (b. 1884) and Fanny Ann (b. 1888).
When the family appeared on the 1891 census they were living at an address in Chorley New Road, Horwich, Lancashire and they would still be at this address by the time of the 1901 census. At the time of the latter record, William was described as an apprentice electrical engineer. He served his apprenticeship with the Electrical Department of the Lancashire and Yorkshire Railway and was later appointed to Harland & Wolff as an assistant manager in the electricians' department, overseeing the fitting-out of ships.
He was married in Cheshire in the latter half of 1910 to Gertrude Poole (b. 1881 in Cheshire). William's job took them to Belfast where he would work for Harland & Wolff and the couple show up on the 1911 census living at 16 Elaine Street, Cromac, south Belfast and he was described as a managing electrical engineer. The couple would later have one child, a son. William was also a teacher in the University Road Methodist Church Sunday School where he was a respected member.
William was one of the nine-strong "guarantee group" of Harland and Wolff employees chosen to oversee the smooth running of the Titanic's maiden voyage. He, like the rest of his counterparts, died in the sinking. His body, if recovered, was never identified.
His widow Gertrude was never remarried and later resettled in her native Cheshire, living at Wood End Cottage in Chester Road, Sandiway. She died on 8 June 1952.