In 1803 Campbell married his second cousin, Matilda Sinclair, and settled in London. He was well received in Whig society, especially at Holland House. His prospects, however, were slight when in 1805 he received a government pension of £200. In that year the Campbells removed to Sydenham. Campbell was at this time regularly employed on the "Star" newspaper, for which he translated the foreign news. In 1809 he published a narrative poem in the Spenserian stanza, "Gertrude of Wyoming" – referring to the Wyoming Valley of Pennsylvania and the Wyoming Valley Massacre – with which were printed some of his best lyrics. He was slow and fastidious in composition, and the poem suffered from overelaboration. Francis Jeffrey wrote to the author: