Before the 19th century, the main businesses of Slough were brickfields and agriculture. The bricks for the building of Eton College were made in Slough. Later, as the Great West Road traffic increased, inns and pubs sprang up along the road to service the passing trade. Until the town developed as an industrial area, nurseries were prominent in the local economy; the Cox’s Orange Pippin apple was first raised in Colnbrook (not then within Slough) around 1825, and the dianthus “Mrs Sinkins Pink” was first raised at some point between 1868 and 1883 by John Sinkins, the master of the Eton Union Workhouse, which lay in Slough.

In the mid-19th century the only major employer apart from the brickfields was James Elliman, who started as a draper in Chandos Street. In 1847, he changed business and manufactured his Elliman’s Embrocation and Royal Embrocation horse liniment at factories in Wellington Street and Chandos Street. Elliman became a major benefactor to the town, and is remembered today in the names of local roads and schools.

In September 1851 William Thomas Buckland, an auctioneer and surveyor from nearby Wraysbury, began livestock sales in a field near the Great Western Road Railway Station belonging to the North Star Inn. Originally held on the first Tuesday of every month, the Cattle Market’s popularity soon saw this increased to every Tuesday. A move to Wexham Street was necessitated by the postwar redevelopment of the town. The Slough Cattle Market was run by Messrs Buckland and Sons until its final closure in 1988.

In 1906, James Horlick, one of the eponymous founders of the malted milk company, opened a purpose-built red-brick factory near Slough Railway Station to manufacture his malted milk product.