Between 1800 and 1860 the population of Glasgow increased more than five-fold to around 420,000. While the richer citizens moved to the suburbs, the influx of migrants from Ireland and the Highlands caused massive overpopulation in the inner city. There were two types of working-class housing; the ‘made down houses' - former middle class homes where each room might house an entire family - and traditional tenements, often without running water or sanitation. In 1866 the City Improvement Trust was tasked with demolishing the old buildings and replacing them with wider roads and larger tenements. Although these slum clearances in part shifted the problem of overcrowding to other areas, they did wipe out epidemic diseases such as cholera and typhus.
After the city passed an act through parliament to demolish the slums of central Glasgow in 1866, Thomas Annan was asked to record the buildings that were coming down. He worked in conditions as bad for photography as they were for humans and took only about thirty successful photographs in the three years he spent on the commission.
Having begun his career as a lithographic writer and engraver on a local newspaper in Fife, Thomas Annan set up a studio as a professional photographer in 1855. He founded his own photographic printing works in Hamilton in 1859 and by 1862 had begun to establish a reputation for photographing works of art. In 1866 he purchased the carbon process patent rights for Scotland and in 1883 he secured the British rights for photogravure. Between 1868 and 1871 he executed a commission from the City of Glasgow to photograph the slums of the old town before their demolition.