His grandfather had been domestic physician to Frederick the Great, and wrote a French romance, Histoire des Diables Modernes.

His father lived for a time in London supported by a wealthy uncle, who provided the son with education, and sent him at the age of fifteen to be placed in the office of his agent for some estates in St. Kitts.

[1] The success of his history and the influence of Archdeacon William Coxe brought Adolphus into close connection with Henry Addington, then prime minister.

He wrote the memoirs in the British Cabinet (1799), a series of portraits of more or less distinguished Englishmen and Englishwomen, from Margaret of Richmond to the second Lord Hardwicke.

[1] In 1818 he published, in four volumes, The Political State of the British Empire, containing a general view of the domestic and foreign possessions of the crown, the laws, commerce, revenue, offices, and other establishments, civil and military; in 1824, Observations on the Vagrant Act and some other Statutes, and on the Powers and Duties of Justices of the Peace, in the main a protest against some "nanny state" legislation of the time; and in 1839 the Memoirs of John Bannister the actor, whom he had known well.

His final contributions to periodical literature were biographical sketches of William Garrow and John Gurney for the Law Magazine.

Their children were: After his death his daughter Emily wrote Recollections of the Public Career and Private Life of the Late John Adolphus The Eminent Barrister and Historian, with Extracts from His Diaries.