Henry Morse Stephens,
Dictionary of National Biography…
(1885)
“ ABERCROMBY, Sir JOHN (1772–1817) , general, was the second son of the famous Sir Ralph Abercromby, and the elder of the two sons who followed their father's profession. He entered the army in 1786 at the age of fourteen, as ensign in the 75th regiment, of which his uncle Robert was colonel. He became lieutenant in the same regiment in 1787, and captain in 1792, and first saw service as aide-de-camp to his father in the campaigns in Flanders in 1793 and 1794. His father's military reputation and dependence on his services caused him to rise rapidly. ”
