Spearman was a descendant of John Spearman, a distinguished lawyer, who in 1678 had purchased Thornley Hall, six miles south-east of Durham.
At the 1847 general election Spearman offered in the Liberal interest for Durham City, pledging to support Lord John Russell’s ministry as he had ‘perfect confidence in the men and hearty approbation of their measures’.
Initially a steady attender, Spearman duly backed Russell’s ministry on most major issues, including the repeal of the navigation laws, 12 Mar. 1849, and John Arthur Roebuck’s motion in support of the government’s foreign policy, 28 June 1850.
Spearman, however, made no impact beyond the lobbies. He is not known to have made any speeches or served on any select committees. He rarely attended Parliament in his last session, and there was little surprise when he stood down at the dissolution in 1852. Following his retirement ‘he devoted a good deal of his time and attention to the pursuit of agriculture’ and became high sheriff for Durham in 1860.
