The biggest change was in their destination - America became Britain's biggest market. Scarcely interrupted by the War of Independence (1776-83), in 1800 nearly 60 per cent of Britain's exports crossed the Atlantic (a proportion that declined as the USA industrialised and British trade and empire turned eastward). The other major cargo was human - British merchants were responsible for shipping over three million slaves (half the total), from Africa, to the slave plantations of the Caribbean and southern USA, before the trade's abolition by Parliament in 1807.
' Tea-swilling, cotton-clad Britons could scarcely complain of the import duties they had to pay ...'
Driving this Atlantic trade was British demand for plantation produce - industrial raw materials, such as cotton and dyestuffs, and exotic groceries, in particular sugar. Sweet-toothed Britons consumed 20 pounds of sugar per head by 1800 - five times as much as a century before - and most of it in their tea, another exotic import, from Asia.
Underpinning the trade was Europe's largest and most expensive navy, keeping the sea lanes open, suppressing pirates and, in frequent wars, stripping the French of their Caribbean colonies. The Royal Navy was, by far, Britain's biggest enterprise and investment, uniquely responsible for the huge rise in government spending during the 18th century. Tea-swilling, cotton-clad Britons could scarcely complain of the import duties they had to pay to help maintain it!
Sugar was, however, more than a morale-booster for British workers. It contributed important calories to a diet which domestic agriculture was struggling to supply. In 1800 imports of staple foods, such as grain, butter and meat, were still small in comparison with a century later, but vital nonetheless. Ireland was Britain's biggest single supplier.
This is not to underestimate the achievement of British farmers in largely feeding the fast-growing population. During the 18th century they brought 50 per cent more land under cultivation and increased yields per hectare by the application of new techniques that allowed more animals to be raised and thereby improved the fertility of the soil.
At the same time, less labour per hectare was required, owing to the increasing size of farms and the resultant economies of scale. In industrial regions redundant workers were snapped up, elsewhere they languished, rarely employed outside harvest time.