The Court of Common Pleas, is so called, because in that court are debated the usual or common pleas between subject and subject, and all civil causes whatsoever; the sittings of this Court are also held occasionally, out of term, in the city.

Mogg's New Picture of London and Visitor's Guide to it Sights, 1844

From the Exchequer Court we pass to the next, which is the Court of Common Pleas. This is held in a smaller apartment, and one of much more humble appearance. The lawyers monopolise the whole of the sitting accommodation there is, and the public, who want to see and hear, have to crawl over the high wainscotting in the rear, and catch what they can of the proceedings. The case which is going on is of no great importance, being simply a question of railway charges for the carriage of goods, and consequently the auditors not immediately interested are few ; and of those who stroll in, the major part soon stroll out again in search of more exciting entertainment elsewhere.
    We may as well state here, that the Court of Exchequer, of Queen's Bench, and of Common Pleas, are also, for the convenience of citizens, held at the Guildhall, in the city, during four specified days of each term.

The Leisure Hour, 1858