The plan records a small skirmish in Shanghai during the years of the Taiping Rebellion (1850-1864). The skirmish between Imperial Chinese forces on the one side and British, American, and rebel troops on the other, took place on the 4th April 1854, and would become known as 'The Battle of Muddy Flat'.

In 1853, a small rebel force known as the 'Small Swords' captured the city of Shanghai. By the end of the 1853 the Qing Dynasty had sent a force of some 20 to 30,000 men to recapture the city, under the command of General Keih. Unfortunately, the army came into conflict with not only the rebels but also the newly formed British and American settlements (formed as a result of the Treaty of Nanking), which was situated just to the east of the old city walls. The Settlers at first took a neutral position, however, after numerous incursions by ill-disciplined imperial soldiers, the settlers decided to take military action; and so on the 4th April 1854 a group of 350 men – many from the newly formed Shanghai Volunteer Corps – advanced (with great trepidation) towards the Imperial camp. The fear of the troops was unfounded, and with the help of the rebels they found little resistance as they took the Imperialists camp. The reasons for the ease of victory are unclear but it has been suggested that General Keih seeing the Amercian and British advance gave the order for his troops to retreat.

Whatever the reasons for the victory it was obviously seen by the Settlers as a great victory against a much superior force. A victory that was still celebrate and remembered by them almost 30 years later.