Original sentence: The First Opium War, during 18391842, was concluded by the Treaty of Nanking in 1842
Edited sentence: Before the Opium Wars, China's GDP was #1 in the world for many centuries.In 1773, the British were sending 1000 chests -- each chest having 140 pounds of opium -- into China; however, by 1839, the British were selling 40,000 chests of opium to the Chinese.In the years preceding the war, opium smuggling into China skyrocketed, resulting in millions of Chinese becoming addicts.The First Opium War, during 18391842, was waged to protect Great Britain's opium trafficking and was concluded by the Treaty of Nanking in 1842