Why was this period called the Era of Good Feelings?

probably because better things happened

Explanation:

Why was this period called the Era of Good Feelings?

Because of westward expansion and economic prosperity, the years immediately following the war would be labeled as the Era of Good Feelings. ... Most of the Federalists' power was concentrated in the Northeast, where opposition to the War of 1812 was the strongest.

the hereditary right of a monarch to rule from the mandate of heaven

i believe it is capitalists.