Son of Richard Roser and Fanny Read, both of England, husband of Caroline Frances Boggis, whom he married on July 27, 1873 in Lambeth, Surrey at Brixton, St. John the Evangelist, England and father of Caroline Frances, Eleanor Kate, Harry George, Mary Louise (married Gerlach), John Stapley, William Richard, Thomas Claver, Joseph Francis, Hester (1889-1889), James Lowe (1890-1891), Lillian Hannah (married Moebus, married Maltz), Florence Keziah (married George F J. Ruthig), Edward Andrew Gerlach, John A., and George William Roser.

Harry Roser had several children, four of whom died in childhood. At the time of his marriage to Caroline, his occupation was given as signal fitter. He was originally buried in Brooklyn, NY.

In 1881, Harry Roser, aged 31, was living at 27 Reeves Road, Bromley St. Leonard, London, England, with his wife, Caroline Frances Roser, aged 28, and children, Mary Louise Roser, aged 2, and John Stapley Roser, aged 11 months. Harry was shown to be a Railway Signal Contractor.

In 1900, Harry Roser, aged 50, was living in Brooklyn, NY, with his wife, Caroline F. Roser, aged 48, with children, Harry G. Roser, 28, Mary L. Roser, 21, William R. Roser, 18, Thomas C. Roser, 15, Joseph F. Roser, 12, Lillian H. Roser, 8, Florence K. Roser, 6, and Edward A.G. Roser, aged 2. Harry was shown to be a switch inspector.

At the time of his death, his widow, Caroline F. Roser, of 48 Duffield Street, petitioned the Kings County Court for the estate of her husband, who died without a will, stating that his heirs were; Harry G. Roser, Mary L. Gerlach, William R. Roser, Thomas C. Roser, Joseph F. Roser, Lillian H. Moebus, Florence K. Ruthig, and Edward A. Roser.

(Records of Cedar Grove Cemetery; Harry Roser in the London, England, Church of England Marriages and Banns, 1754-1921; 1881 England Census; 1900, 1910 US Federal Census; New York, New York City Municipal Deaths, 1795-1949, Reference ID 3664, GS Film Number 1324273; New York, Wills and Probate Records, 1659-1999 for Harry Roser; The Brooklyn Daily Eagle (Brooklyn, New York), Tuesday, February 16, 1915, page 20)