In the late-nineteenth century, during what is known as the "Third Party System," both the Republican and Democractic parties split into multiple factions. The Democrats had three broad bases of support: Southern Whites, favoring populist economics and racial political appeals; Northern Urban residents, favoring populist economics and labor movements; and the Bourbon Democrats. The Bourbons, referring to conservative factions in Europe, combining support of laissez-faire capitalism, particularly siding with fewer restrictions on banks, railroads, and other corporations, with vigorous civil service reform, as the Bourbons were sworn enemies of the bosses that controlled the party in large cities.

The Lecompton Constitution was one of many proposed constitutions for the state of Kansas. The Lecompton Constitution enshrined slavery in the state of Kansas and guaranteed protection for slaveholders. Ultimately, the people of Kansas and the House of Representatives rejected the proposal and Kansas was ultimately admitted as a free state in 1861; however, the effect of the Constitution was significant in breaking up the Democratic Party and contributing to the phenomenon of “Bleeding Kansas.”

Anti-federalism opposed the creation of a stronger, more centralized Federal government. Patrick Henry, James Monroe, and Samuel Adams were all members of the Antifederalists. At the Constitutional Convention of 1787, led by Henry, Antifederalists opposed the ratification of the Constitution. They argued, among other things, that the position of the President might evolve into a position of monarchy and tyranny. 

The Democratic-Republican Party formed around the political ideologies of, primarily, Thomas Jefferson and James Madison. It was formed in opposition the Federalist Party. The Party began in opposition specifically to the plans of Secretary of Treasury Alexander Hamilton—the man who would give the Federalist Party its early direction. The Democratic-Republicans, sometimes called just the Republican Party, functioned as the dominant political expression of ideology from 1801—and the election of Thomas Jefferson—to 1824, and the end of the Era of Good Feelings. 

The Tammany Society arose in the early years of the United States as a political organization comprised of immigrant revolutionary war veterans. It grew in influence throughout the nineteenth century and played a major role in the Democratic Party’s policy making. The Tammany Society campaigned extensively for the rights of Irish immigrants to New York City and gained a massive immigrant support base. It waned in popularity in the early years of the twentieth century. 

The Naturalization Act of 1798 was designed to lengthen the amount of time that resident aliens were required to live in the United States before they could become full and equal citizens. The Naturalization Act of 1795 established a five-year wait before citizenship could be acquired, but the Naturalization Act of 1798 practically tripled this to fourteen years. It was passed as part of the Alien and Sedition Acts—a series of bills designed to ensure the primacy of the Federal government and the Federalist Party. Most historians agree that the primary motivation behind the passage of the Naturalization Act of 1798 was to limit the voting base for the Democratic-Republicans (the majority of immigrants supported the policies of Thomas Jefferson and the Democratic-Republicans). It was repealed in 1802, with the passage of the Naturalization Act of 1802. 

Following his victory in the election of 1800, President Thomas Jefferson sought to implement many of the changes desired by his political party—the Democratic-Republicans. One of the first efforts made to undo the work of the Federalist Party was to repeal the Judiciary Act of 1801, specifically Jefferson wanted to remove the many “midnight appointments” made by John Adams shortly before his Presidency had ended. 

The debates between Senators Robert Hayne and Daniel Webster began over the attempt by North-Eastern lawmakers to establish protectionist tariffs on goods manufactured in New England. Many Southern Congressmen felt that this was a deliberate provocation designed to stifle economic growth in the South so that the North could achieve greater economic prominence. The debates that raged between Hayne and Webster captured the imagination of contemporary audiences and the speeches are still quoted to this day. Webster’s “Second Reply to Robert Hayne” is considered one of the finest oratorical speeches in American history. 

The 1803 case, Marbury v. Madison, established the power of Judicial Review. Granting the US Supreme Court the ability to declare laws unconstitutional.

Lincoln's thinking on emancipation evolved greatly over the course of the Civil War. When the war first started, Lincoln had no intention of emancipating the slaves. He was not, necessarily, in favor of slavery, but he recognized it as part of the economy of the south.

Due to the Haitian Revolution, in which the slaves of the nation of Haiti rose against their masters and took over the island, whites in the US were constantly fearing a slave uprising. President Lincoln also worried that if slaves were released they would immediately rise against their masters and take up arms against all white people.

In addition, Lincoln did not have the right to emancipate the slaves. The Constitution forbid the government, in more ways than one, from doing anything that would result in the ending of slavery; however, Lincoln expanded the power of the presidency during the Civil War and through his actions he did, in fact, emancipate the slaves.

Throughout the war the north was afraid that other countries would get involved in the conflict, particularly that they would side with the Confederacy. Since slave labor provided many raw goods that were utilized in Britain and France, the Union was afraid of international involvement if they tampered too much with production.

Lincoln felt that slavery was ingrained in the southern way of life. More than anything he wanted to keep the Union whole. He feared that if he emancipated the slaves than the Confederate states would never rejoin the Union and continue to resist until they won or until they were completely decimated by Union forces.