Dickson attended the Royal Military College, Sandhurst, and joined the British Army in 1824.
He served in India, and during the Carlist Wars in Spain, was commander of the 7th Regiment of the British Auxiliary Legion.
He joined the Tower Hamlets militia in 1846 as a major, and was promoted to lieutenant-colonel in 1855, but was demoted in 1858 without any public explanation being given.
[1] Dickson stood unsuccessfully as a Conservative for Norwich alongside the son of the Duke of Wellington.
[2] During the 1850s and 1860s, Dickson was active in the campaign for manhood suffrage, working closely with Edmond Beales.