B/W print; External view of Clapham Common Underground station, 1925

At the start of the 20th century, Clapham was an affluent suburb. The station opened there in 1900 as part of the Central & South London Railway (C.&S.L.R.) extension. Its users were mainly middle-class commuters travelling into the City to work. The line was included in the Tube redevelopments of the 1920s which were aimed at creating a unified identity for the Underground Group. Since most lines had been developed by private companies, there had been no common standard and the C&S.L.R. tunnels needed to be widen to 11' 8¼" (just over 3.5 metres). The work at Clapham Common was completed on 1 December 1924. At 5.30 the following morning, a queue of over 200 people were already waiting.