From the Strange Maps site, the layout of the Clapham Gang:
Long gone are the days when Clapham was a small, rustic village well beyond the gates of medieval London. Also gone, but less long, is the era of Clapham as a fancy suburb fashionable with the upper classes, whose rows of mansions skirted the windy expanse of Clapham Common. We’re talking late 18th, early 19th century here. The area has since gone down in the world. A lot of those mansions are gone, and Clapham these days is a mere district of London, albeit still a not too unpleasant one, thanks in part to the enduring green oasis that is Clapham Common.
This map, dated 1800, depicts the common at what may have been its high society high-water mark. These were the days of the Clapham Saints, a loose association (1) of agenda-setting Anglicans. They were wealthy businessmen promoting abolitionism, prison and debt reform, and other emancipatory causes. Centred on William Wilberforce (1759-1833), whose Bromfield House is the only residence mentioned by name (and circled red) on this map, the Saints were instrumental in pushing through Parliament the Slave Trade Act (1807) and the Slavery Abolition Act (1833), respectively banning the trade in slaves, and slavery itself throughout the British Empire.