was anti-Federalist: they were interested in independence and self-sufficiency. The Federalists were concerned that if their opponents gained control, the Republicans might threaten the Union, property rights and other rights, and might also ally with France. On the Republican side, this party felt that the Federalists favored a monarchial system, just as Britain, and were threatened by government corruption, high taxes, and favor monopolies. By the end of the 1820's, Andrew Jackson was elected president, and the Federalist Party became the Whig Party. Jackson's presidency is significant because the Republican Party split into Democratic-Republicans and National Republicans. The former became the Democratic Party, and thus, the two-party system came into existence. In the 1850's when slavery was a key political issue, the Whig Party became the Republican Party, and they were in favor of abolishing slavery. By the time Abraham Lincoln took office, the importance of political parties can be realized. Political parties serve the interests of different groups, and it is still so today with Republican and Democratic parties.
Before Missouri became part of the Union, the Union consisted of 11 free states and 11 slave states. When Missouri applied to become part of the Union, it meant that there would be 12 free states, but only 11 slave states, and this balance was a threat to government. When northern Massachusetts became Maine, there was some relief: Balance was restored and Missouri was to be a slave state. The admission of Missouri and their status as a slave state later affected politics in the future when Abraham Lincoln would run for presidency.
Bibliography
Paul S. Boyer, et.al., The Enduring vision: A History of the American People Vol.1 - 5th ed. Boston; MA, Houghton Mifflin, 2004