Answer:
He wanted to create a new genre of landscape painting that embedded some sort of moral message for the audience.
Step-by-step explanation:
Most landscape painting only show a simple scenery of nature (such as forest, mountains, sea, etc). It only aimed to show the aesthetic value within the environment around us. Thomas Cole wanted his landscape painting to be different. He wanted to use it as a medium to challenge people's perspective on several issues.
This can be seen in one of his painting , The Course of Empire.
This painting consist of 5 landscapes that depicted different states of empire from its early establishment to its destruction. Through this paintings, Cole wanted to convey that greed of power and limiting people's liberty will eventually led to any nation's downfall.