Tabanus: There was a Fishmonger in London with the same name and of the same age. But I think I found the Esq.:1818: Henry Thomas Young, born 17 March 1818 in Saint Mary-St Marylebone Road, St Marylebone, London, baptized 12 May 1818, Father: Wililam, mother: Louisa. (England, Select Births and Christenings)
1841 census, St Mary, St Marylebone Middlesex: Louisa Young, hd, 50, Louisa, 30, Emily, 20, <Henry, 20, Law.>
1844: <Attorneys to be admitted. Clerks' Name and Residence: Young, Henry Thomas, 16, Cumberland Street, Portman square. To whom articled, assigned, &c.: John Eldad Walters, Lincoln's Inn.> (The Legal Observer, 1944)
1851 census, 16 Cumberland Street, St Mary, St Marylebone Middlesex: Louisa Young, Head, Widow, 62, Fundholder (?), Emily, 34, <Henry T, 33, Practising Solc> (?), Ellen, 31
1857: <CHESS. Problem No. 186, by Henry Thomas Young, Esq., of the St. George’s Chess Club.> (The Era, 15 Nov 1857, p. 14) (the first H. T. Young problem I could find)
1860: Young, Henry Thomas, Esq. 9, New square, Lincoln’s inn, wc, and 59, Cumberland street, Bryanston square, w (London Royal Blue Book 1860)
1861 census, The Palace, Brighton Sussex: H. Thos. Young, Lodger, 43, b. in St. Marylebone Middlesex, Solicitor.
1862: Henry Thomas Young, married 9 Sep 1862 in Alverstoke, Hampshire to Charlotte Isabel Jenyns (England, Select Marriages)
1871 census, Eastbourne Sussex: Henry T. Young, 53, Head, born in Midx Marylebone, Solicitor, Charlotte I, Wife, 39, b. in Bottisham Cambridgeshire, Evelyn H, 5, Minna G, 4, Edward G, 3, Lionel G, 2, Walter C, 3 Months.
1880: <Problem No. 1888. By Henry Thomas Young. (diagram) White to play, and mate in three moves.> (Illustrated London News, 24 April 1880, p. 414)
1880: <YOUNG, Henry Thomas. 7 August. The Will of Henry Thomas Young formerly of 59 Great-Cumberland-place Hyde Park and of 9 Lincoln’s-Inn both in the County of Middlesex but late of Camden Hill near Staplehurst in the County of Kent Solicitor who died 25 July 1880 at Camden Hill was proved at the Principal Registry by Charlotte Isabel Young of Camden Hill Widow the Relict the sole Executrix.> (England & Wales National Probate Calendar)
1880: <Problem No. 1913. By H. T. Young. (diagram) White to play, amd mate in two moves.> (Illustrated London News, 16 Oct 1880, p. 390) (this is the last H. T. Young problem I could find)
1881 census, Camden Hill House, Frittenden Kent: Isabel Young, Head, Widow, 49, Indepent Lady, Mina, 14, Scholar, Mansell G, 7, Scholar.