Throughout the nineteenth century, the town of Markethill evolved rather rapidly, giving it an appearance most people would recognise today. In the opening decades of the century, schools were opened throughout the countryside providing education and opportunity for many young people. The Acheson family of Gosford Estate established an agricultural residential college to aid young men and women in the cultivation of their land. These schools dotted throughout the countryside, were usually held in small cottages but provided an extended community network throughout the countryside.
The 1820s saw the commencement of the building of the present Gosford Castle, a sign that the estate seemed to be flourishing. There came, too, the erection of Saint James' Catholic Church at Drumlack for the congregation who had worshipped until then in a mass garden in Gosford Estate. In 1822, the town of Markethill was granted a new cloth market encouraging activity in the town and expanding the existing economic life of the area.
Over the following decades came the rebuilding of Mullabrack Church of Ireland in 1830, the erection of a Methodist Church in 1833 and the erection of two hotels, the Gosford Arms Hotel and the Kings Arms Hotel. In 1835, on the recommendation of William Greig, a Markethouse was constructed giving a permanent home to the markets and fairs held within the town of Markethill. A few years later, in 1842, the present Courthouse was built as a home for the petty sessions court of the district. Though these buildings have long since relinquished their initial functions they are still very much a part of the commercial and architectural life of the town.
1861 was an important year for Markethill with the Great Northern Railway Line being extended into the town. This not only encouraged mobility for the inhabitants of the area but also gave a boost to the commercial life of the town. Bringing raw materials from Armagh and other large towns the train would be emptied and then filled with the produce of the district for sale in the Armagh market.