Final answer:
In early 19th-century America, artists began developing a distinct American style, particularly in landscape painting, which mirrored the nation's burgeoning identity, democracy, and westward expansion. This period also saw significant national developments, such as the Louisiana Purchase and the onset of the industrial age.
Step-by-step explanation:
The phrase 'Art Essence of America between 1800-1820' refers to the early development of a distinct American art tradition during this time period. Although early American artists were still influenced by European styles, a truly American style began emerging, particularly with the advent of landscape painting that encapsulated concepts of the new nation and its natural wonders.
This was a manifestation of American Realism, a genre that depicted heroic American life, the theme of democracy and westward expansion, differentiating itself from European religious art or depictions of royalty. When discussing this period, it's important to also recognize the broader historical context, which includes the Louisiana Purchase, westward expansion, the impact on Native American tribes, and the beginning of the industrial age characterized by agricultural plantations, railroads, and manufacturing.