Who served as u. s. president for much of the era of good feelings?

President James Monroe

Although the “era” generally is considered coextensive with President James Monroe's two terms (1817–25), it really began in 1815, when for the first time, thanks to the ending of the Napoleonic Wars, American citizens could afford to pay less attention to European political and military affairs.

Your answer is James Monroe

byzantine empire is the answer i think you are looking for.

hope this : )