The ninth President of the United States who died in office from pneumonia complications after having served only 32 days was William Henry Harrison. Harrison was, until Ronald Reagan, also the oldest person ever to assume the office of President.

On July 2nd, 1881, Charles Guiteau shot President Garfield, causing his death.  Guiteau acted as a disgruntled seeker of a Federal office who blamed President Garfield for his situation.

Robert E. Lee took command of the army of Northern Virginia in June of 1862. The army was the principle Confederate fighting force in the Eastern theatre of the Civil War—fighting in the battles of Antietam, Fredericksburg, Gettysburg, Chancellorsville, Second Bull Run and many others. The army also included a corps led by Lt. Stonewall Jackson. 

The battle of Antietam (Sharpsburg) was the bloodiest single-day battle of the Civil War, with over twenty thousand casualties. The battle was fought between the Confederate army of Northern Virginia against the Union forces, led by George McClellan. The battle of Antietam ended Lee’s invasion of the North and forced the Confederate army to withdraw to Virginia. Following the culmination of the battle President Lincoln issued the Emancipation Proclamation. Gettysburg was the bloodiest battle, but it lasted longer than one day.

Andrew Jackson is most often remembered as a President who applied the “spoils system” to the appointment of government officials. Individuals who had supported Jackson throughout his electoral campaign, or who remained loyal to him throughout his political life, were rewarded with positions in government once Jackson became President. Jackson famously broke with his Vice-President John C. Calhoun in 1831 and dismissed a large percentage of his cabinet who he deemed disloyal. He replaced them with his friends and personal advisors, many of whom had little political experience. This collection of advisors has been termed the “Kitchen Cabinet.”

"The Kitchen Cabinet" was the name given to Andrew Jackson’s collection of friends and advisors that he assembled during his Presidency. The term was used, mostly by Jackson’s opponents, disparagingly. The Kitchen Cabinet came into being following the dismissal of Vice-President John C. Calhoun, along with several other cabinet members. Most historians believe that Calhoun was dismissed for his refusal to support Jackson during the Eaton Affair (a scandal between a widowed woman and Jackson’s close friend Eaton).  

In 1884, Grover Cleveland was elected President on a coalition of pro-business "Bourbon Democrats" and reform minded "Mugwump" Republicans. When he ran for reelection in 1888, he lost to Republican Benjamin Harrison. Four years later, Harrison and Cleveland squared off again in the Presidential election, with Cleveland returning to the White House. To date, he is the only President to serve two non-consecutive terms, and is counted as both the 22nd and 24th Presidents.

Charles Guiteau had desired a government job after supporting the candidacy of James Garfield in the 1880 Presidential Election. After repeated requests for a diplomatic post in the early months of 1881, Guiteau was banned from a variety of government buildings. At this, Guiteau turned to taking revenge on the new President, bought a pistol, and stalked Garfield's every movement. On July 2, 1881, Guiteau approached Garfield as he was leaving for vacation at the Baltimore and Potomac Railroad Terminal. Guiteau shot him in the back, and instantly was arrested. Garfield lay dying for months, and even was transferred to the Jersey Shore to recuperate. On September 19, 1881, Garfield passed away, and Guiteau was hanged on June 30, 1882. The largest consequence of the assassination was the Pendleton Civil Service Reform Act, that both fulfilled a goal of Garfield's and systematized the hiring of government employees.

Texas had been a Republic since 1836, and wanted to become the newest state, making Texas' statehood a most controversial issue in the 1844 Presidential Election. James K. Polk, the first true dark horse in American Presidential politics, won the Democratic nomination and the Electoral College by promising large expansion of American Territory, particularly promising to annex Texas. Texas became a state in 1846, under Polk's auspices.

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.