The "Era of Good Feelings" was a time of complete republican dominance over the federalists which was further established by James Monroe's goodwill tour where he was even welcomed by Federalist New England. It was time of greater nationalism but Sectionalism also began rising throughout the country and eventually played a bigger role in the country than nationalism. The So Called Era of Good Feelings was actually not filled with good times and thus the label of this era is not very accurate. Issues with Sectionalism including problems with the bank of the United States, the Protective Tariff, internal improvements, Missouri Crisis, and the Denmark Vesey incident were all reasons why this era wasn't so good.
In Document A, John Randolph points out a major problem during the era. The government was treating the poor agriculturalists unequally compared to the wealthy manufacturers. The government preferred manufacturers over farmers and thus worked to benefit them more. The farmers, because they were paying much more taxes, remained poor while the rich manufacturers were swimming in their own wealth. This relates to the Protective Tariff that was passed to protect businesses. It was pretty much a symbol of sectionalism because it really divided the northeast and south. The tariff mostly benefited manufacturers in the north while the southern farmers were taking all the heat. They were the ones paying higher taxes due to the tariff while manufacturers were using it to their advantage. This issue served to show that the label given to this era was is not very accurate because of the sectionalism it created. .
Document B is another example in which John C. Calhoun expresses the issues of sectionalism. He stated that disunion was the biggest problem the country faced. America was growing at a massive rate and Calhoun showed his nationalism by providing a solution to keep the country undivided.