What treaty ended the Opium Wars in 1860?

The treaty that ended the Opium Wars in 1860 is known as the Treaty of Tientsin. This treaty was a result of the Second Opium War, which involved conflicts between Britain and China over trade imbalances and the continuing opium trade. The Treaty of Tientsin, signed in 1856 but finalized in 1860, established several key provisions, including the opening of new ports to foreign trade, the legalization of the opium trade, and allowances for foreign legations in Beijing.

The Treaty of Nanking, signed in 1842, concluded the First Opium War and set the stage for subsequent conflicts, but it is not the treaty associated with the resolution of the Second Opium War. The Beijing Convention and the Sino-British Agreement do not directly relate to the end of the Opium Wars. Thus, the Treaty of Tientsin is the appropriate answer as it specifically addresses the agreements made following the conclusion of hostilities in 1860.