The turbulent years of the 1640s and 1650s had set back Cork's economic development. The city began to recover in the period from 1660 to 1700, and the eighteenth century witnessed a major expansion in the economy of Cork. The economic prosperity of Cork in the eighteenth century was based mainly on the provisions trade. Salted beef, pork and butter were exported to the West Indies and were used to provision the British navy. The unrivalled ability of Cork Harbour to shelter the biggest fleets assembled during the American War of Independence and, later, during the Napoleonic Wars was a major factor in the expansion of the provisions trade in Cork. Cork Butter Market, with its strict and rigorously enforced system of quality control, was world famous and became the largest butter market in the world for its time.
The textile industries also flourished in Cork during this period. The demand for linen for sailcloth helped the growth of the Douglas sailcloth factory which was the biggest such factory in Europe by 1726. The Besnard family became the owners of this sailcloth factory later in the century. The woollen and cotton industries were very important with O'Mahony's Woollen Mills in Blarney and Sadleir's cotton mills in Glasheen being particularly prominent.
The late 1700s saw the tanning, brewing and distilling industries flourish. The Beamish and Crawford brewery established in 1792 became the biggest of its kind in Ireland and was a major employer in Cork until its closure in 2009.
The close links of Cork's economic prosperity to the war economy and the export of salted goods were weaknesses that were exposed in the period of peace following the Napoleonic Wars and later by the development of refrigeration.
The economic development of Cork in the eighteenth century was mirrored by the physical development of the city during the same period. After the partial destruction of the city's walls during the Williamite siege, the city began to expand rapidly in the area outside the walls and began to take on a recognisably modern configuration. Dunscombes' marsh and the Reap marsh between St. Patrick's Street and the South Mall were reclaimed as was Hammond's marsh on the west of the city. The river channels between the marshes were infilled to form St. Patrick's Street, the Grand Parade, Henry Street, Grattan Street, Cornmarket Street, Sheare's Street and other streets. By 1790, the outline of the city centre as we know it today was established.
The late eighteenth century also saw the construction of bridges linking the centre of the city to the suburbs. The first St. Patrick's Bridge, Parliament Bridge and Clarke's Bridge all date from this period. The North and South Gate Bridges had been rebuilt in the 1710-1715 period. The South Gate Bridge has one of the oldest surviving three-centered arches in Ireland. Along with the growth of the city went an increase in the population. Prior to the first proper census, which dates from 1821, figures for the population of the city can only be estimates. The population of Cork city was approximately 20,000 in 1675. This is estimated to have risen to about 25,000 by 1700. Estimates for the population in the mid 1700s vary from 40,000 to 56,000. For the late 1700s, estimates vary from 52,000 to 80,000. What is not in doubt is that the population of the city had grown enormously during the eighteenth century. Despite the economic prosperity of Cork during the eighteenth, poverty was widespread among the lower classes and food riots during periods of food shortages were quite common. The records of the period bear witness to the scourges of drunkness and violence which has their roots in privation and poor living conditions.
The prosperity of Cork and Ireland during the eighteenth century owed much to the political stability of the century after the tumult of the seventeenth century. However, the stability disguised undercurrents of dissension and dissatisfaction. These feelings were due largely to resentment at the concentration of all political power and most economic power in the hands of the minority Ascendancy class. The eruption of the underlying discontent and disaffection in the 1798 Rebellion brought havoc and carnage to those parts of Ireland most affected by the outbreak.
While Cork city was relatively untouched by the Rebellion itself, the United Irishmen had been active in the city for some time prior to the outbreak. The military authorities took severe action against those found guilty of being members of the United Irishmen. Many were transported and many shot by firing squads in a field on the western edges of Cork city, through which the Western Road now runs. The National Monument on the Grand Parade commemorates some of those who suffered in the aftermath of 1798.