There is one letter to Mary Caldwell, Henry's sister, written in 1865. Other papers include watch bills 1848-1851 and 1856; a night order book, 1859-1862; printed papers; exercise books for the period at the Royal Naval College and remark books and notes relating to his various ships.

See item level records for further details.

Administrative / biographical background
Caldwell, grandson of Sir Benjamin Caldwell (q.v.), entered the Navy in 1828 as a volunteer on board the Dartmouth and became a midshipman in the Prince Regent in 1830. He served for the next five years on the coast of South America in the Clio, Spartiate and Hornet and then in the Pembroke and Vanguard on the Mediterranean Station. After this he spent three years in the brigs Pantaloon and Rapid, tenders to the Royal George yacht. Caldwell was promoted to lieutenant in 1841 and for two years attended courses in the Excellent on gunnery and at the Royal Naval College on steam. He then served in the Inconstant on the Mediterranean Station from 1843 until 1846, when he joined the Excellent and Prince Regent, home waters. From the latter ship he was promoted to commander in 1847. In 1848 he joined the Powerful on the Mediterranean Station and returned to the Prince Regent in 1851. He was promoted to captain in 1853 and after studying steam at Woolwich dockyard, became Flag Captain to Rear-Admiral Hon. R.S. Dundas (1802-1861), Commander-in-Chief Baltic, in the Duke of Wellington, and remained in her until 1857. Caldwell joined the Mersey in 1859 for three years, serving in the Channel and on the North American and West Indies Station. After a short period in the Royal Adelaide at Devonport, he joined, in 1864, the Asia, guardship of the steam reserve at Portsmouth. Finally Caldwell was aide-de-camp to Queen Victoria from 1866 until his death.