From the article:
The title refers to Brother Jonathan, a popular personification of New England and the broader United States. The story follows protagonist Walter Harwood as he and the nation around him both come of age through the American Revolution. The novel explores cross-cultural relationships and highlights cultural diversity within the Thirteen Colonies, stressing egalitarianism and challenging the conception of a unified American nation. It features mixed-race Anglo-Indigenous characters and depicts them as the inheritors of North America. The book's sexual themes drew negative reactions from contemporary critics. These themes were explicit for the period, addressing female sexual virtue and male guilt for sexual misdeeds, which was an abnormal topic in the 1800's.
https://catalog.hathitrust.org/Record/001692793