In the decades immediately following the Civil War, the Republican Party held a monopoly on the White House and filled the Presidency with a number of Civil War veterans. Not all of these presidents served similarly. Grant was the final commander of all Union forces.  Garfield and Hayes both served admirably in the field, and Arthur was a quartermaster in the Union forces. Buchanan was a Democrat who was President 1856–1860, immediately preceding the Civil War.

The American Party was formed in the 1850s, primarily among Northern cities. Their chief organizing principle was opposition to the recent influx of immigrants, particularly Irish immigrants fleeing the Famine in Ireland. In a time of constant division over slavery and westward expansion, the American Party focused strictly on opposition to immigration. Their nickname came from the supposed response of its members when they were asked if they were members, "I know nothing." By 1860, the Know Nothings became one of the cornerstones of the brand new Republican Party, along with Reform Whigs, Free Soil Democrats, and other smaller parties.

The 1824 Presidential Election was the most convoluted and confusing elections in American History and was contested by four men, Secretary of State John Quincy Adams, Speaker of the House Henry Clay, Secretary of the Treasury William H. Crawford, and military hero, former Governor and Senator from Tennessee Andrew Jackson. With this four way election, no man won enough votes for the Electoral College to decide the contest, and the election went to the United States House of Representatives, as provided by the Twelfth Amendment to the Constitution. Only the top three vote getters were considered, ruling out Clay, who also had an animosity toward Jackson. Thus, despite Jackson receiving many more votes, winning more states, and having more electoral votes, John Quincy Adams was selected as President by the House.

William Henry Harrison, a former Senator from Ohio and noted Indian fighter, defeated President Martin Van Buren in the 1840 Presidential election, pledging to stop the ongoing economic depression and unifying the new Whig Party. During his Inauguration on March 4, 1841, Harrison refused to wear an overcoat, turned down a ride in a covered carriage, and gave the longest inaugural speech in U.S. History, despite the cold and damp weather in Washington. Within a month, Harrison had contracted Pneumonia, and on April 4, 1841 passed away. His Vice President John Tyler then took the oath of office as President. Many detractors only called Tyler the "interim President," as he was elected only Vice President, but Tyler set in place the precedent codified by the Twenty-Fifth Amendment in 1967.

Only four Presidents have been assassinated, Abraham Lincoln, James A. Garfield, William McKinley, and John F. Kennedy. Other Presidents have died in office, and were succeeded by their Vice Presidents, including William Henry Harrison, Zachary Taylor, Warren Harding, and Franklin D. Roosevelt. Many nineteenth-century Presidents served one term, often out of choice. Most notable of these was James Polk, who only served one term from 1845–1849, and left office after accomplishing many of his campaign goals.

"The American System," was the chief policy guide for the Whig Party during the Second Party System of the 1820s to the 1850s. First formulated by its chief spokesman, Speaker of the House Henry Clay of Kentucky, the American System advocated for a series of "internal improvements," in particular the building of railroads, canals, and other transportation networks. With this, the Whigs also sought a protectionist tariff and an economic populism.

The Treaty of Greenville was signed by American frontiersman and a collection of Native American peoples in 1795. The treaty established the “Greenville Line,” which served as a boundary between Native people and American and European settlers for several years; however, the settlers soon began to encroach on Native American land in direct violation of the treaty. 

Delaware was the first state to ratify the United States Constitution, on December 7^th, 1787. The last of the original thirteen states to ratify the Constitution was Vermont. 

The Battle of Tippecanoe was fought during the war between American settlers and Native American forces led by Tecumseh. William Henry Harrison, then governor of Indiana, led the American forces into conflict. It is generally considered to be a victory for the forces of the United States and it served as an important piece of personal propaganda for William Henry Harrison. He acquired the nickname "Tippecanoe," and when he ran for President the slogan “Tippecanoe, and Tyler too” greatly advanced his popularity with the common man. 

The Battle of Horseshoe Bend was fought between American forces, led by Andrew Jackson, and their Native American allies against the Creek Indians. It is considered part of both the War of 1812 and the Creek War. The battle saw the complete massacre of the Creek forces and ultimately the surrender of the Creek war effort.