The right of election in Cockermouth was vested in the burgage tenants of the borough, of whom there were about 300 in 1832. Cockermouth was considered a pocket borough, with the vast majority of the voters being under the influence of the Lowther family.
At the time of the 1831 census, the borough included just over 1,000 houses and had a population of 4,536. The Reform Act expanded the boundaries to bring in the neighbouring parishes of Eaglesfield, Brigham, Papcastle and Bridekirk, and part of Dovenby, increasing the population to 6,022 and encompassing 1,325 houses. This made the borough big enough to retain both its members. However, in the next wave of reform, introduced at the 1868 general election, one of Cockermouth's two seats was withdrawn, and in 1885 the borough was abolished altogether, although the name was transferred to the surrounding county constituency.
The Cockermouth constituency created in 1885, strictly speaking The Cockermouth Division of Cumberland, was a compact division stretching westwards from Cockermouth to the sea, and including the much larger town of Workington. There was a significant Irish vote, and the Conservative victory in 1885 and subsequent Liberal gain of the seat in 1886 have been attributed to Parnell's shift of support from the one party to the other.
Another General Election was required to take place before the end of 1915. The political parties had been making preparations for an election to take place and by the July 1914, the following candidates had been selected;
^Fenwick was later elected for Northumberland, which he chose to represent, and ceased to sit for Cockermouth
^The election to replace Fenwick was disputed, and the Returning Officer made a double return, i.e. reported both candidates - Sir Thomas Sandford, Bt and Francis Allen - as elected, leaving Parliament to decide. The dispute was still unresolved when Sandford was declared disabled from sitting because of his Royalist sympathies in January 1644; Allen was admitted to sit in 1645.
^In a by-election in 1717, Seymour was defeated by Sir Wilfrid Lawson by 90 votes to 84, but Lawson was underage, and on petition Seymour was declared elected
^Wyndham was also elected for Taunton, which he chose to represent, and never sat for Cockermouth
^Created Earl of Thomond (in the peerage of Ireland), 1756
^Johnstone was re-elected at the general election of 1774, but was also elected for Appleby, which he chose to represent, and did not sit for Cockermouth in this parliament
^Norton was also elected for Carlisle, which he chose to represent, and never sat for Cockermouth