James Wyld's series of maps of China were issued during the First Opium War (1839-42), a conflict sparked by Chinese attempts to control the sale of opium on China by Britain. The dispute arose because of a trade discrepancy between the two countries: although there was a healthy market for Chinese goods in the west, China had little interest in British exports, and insisted on being paid for goods in bullion rather than goods in kind. In order to replenish bullion stocks, the British exported opium from their central Asian territories and sold it in China. The war was an exercise in gunboat diplomacy, where the British navy used their firepower advantage to win a decisive victory over the Chinese. It ended with the Chuenpi Convention in 1842, when Hong Kong was granted to the British as a trading post.

In the map China is divided into provinces by pink lines, but the importance of trade to the conflict is reflected by the addition of the names of various export goods alongside place names, like the "granite district". It also contains several insets showing key cities and battles in the war.

James Wyld (1812-1887) was a highly successful cartographic publisher, MP for Bodmin, and an active figure in public life. He promoted the development of the British Library and campaigned for the Public Libraries and Museums Bill, accusing its agricultural opponents of trying to make the poor drink instead of read in order to keep malt consumption high; although he did oppose the introduction of the Ordnance Survey on behalf of private surveyors. Like his father, he was made Geographer to Queen Victoria and Prince Albert in 1836. He built his business on his ability to produce maps quickly in reaction to new information and events, like this map of the Opium War: Punch remarked drily that if a country were discovered in the centre of the earth then Wyld would have a new map out "as soon as it is discovered, if not before".