doubled the size of the united states
The Abolition of the Slave Trade Act entered the statute books. Nevertheless, although the Act made it illegal to engage in the slave trade throughout the British colonies, trafficking between the Caribbean islands continued, regardless, until 1811.
This was the Qing dynasty: all the previous dynasties ruled over areas visibly smaller (even by 50%) than today's area of China. The Qing, a dynasty from Manchuria was also the last dynasty.
Before this, the Qin dynasty also united a big number of areas, and in certain contexts, this could also be the correct answer (it united all of today's eastern China).
