Why did merchant classes begin to rise during the Ming?

Explanation:

In 1352, Zhu joined one of the many insurgent forces that had risen in rebellion against the Mongol-led Yuan dynasty. ... The last Yuan emperor fled north into Mongolia and Zhu declared the founding of the Ming dynasty after razing the Yuan palaces in Dadu (present-day Beijing) to the ground.

the compromise of 1850 was a package of five separate bills passed by the united states congress in september 1850, which defused a four-year political confrontation between slave and free states on the status of territories acquired during the mexican–american war

whats the question? im not quite understanding your question.