The square has become a social and political focus for visitors and Londoners, developing over its history from "an esplanade peopled with figures of national heroes, into the country's foremost "place politique"", as historian Rodney Mace has written. Since its construction, it has been a venue for political demonstrations. The great Chartist rally in 1848, a campaign for social reform by the working class began in the square. A ban on political rallies remained in effect until the 1880s, when the emerging Labour movement, particularly the Social Democratic Federation, began holding protests. On 1886 (also known as "Black Monday"), protesters rallied against unemployment leading to a riot in Pall Mall. A larger riot (""Bloody Sunday"") occurred in the square on 1887.