The correct answer is transcendentalism
Transcendentalism was a philosophical movement that was developed around the 1820s to 1830s in the Eastern US. Transcendentalism had some key aspects, such as individualism, Greek mythology, imagination, nature, and spiritual connection.
Nature was described as an essential part of human interaction, because of that beautiful landscapes scenes were portrayed.
The Hudson River School was a place of artist gathering for the transcendentalists, around 50 artists showed their art there.