How and why did the Federalists seem to overreact to the emergence of the Republicans as powerful contenders for national favor? How did the Republicans respond to that apparent overreaction?

The Federalists, who are supporters of the ratification of the Constitution of 1789, which is when it enters into force, reacted excessively to the emergence of Republicans. - which are those who were against, and oppose it, mainly because they lacked a Bill of Rights. -, they react, because until 1800 The federalists were dominant, and the Republicans were dominant after 1800.

And how do they do it, then appealed to the business community.

What the Republicans did, appeal to the planters and farmers. devising a complex multi-faceted program to achieve that goal, and simultaneously solve the debt problem for most states.