Thus at the age of 14, Andrew Jackson was an orphan. He lived with various relatives and worked at different jobs until he moved to North Carolina in 1784 to study law under a prominent trial lawyer. Jackson worked hard and played hard, gaining a wild reputation for his boisterous leisure-time antics, yet passing the bar exam in September 1787. In spring of the next year, he journeyed to Tennessee to accept a post as public prosecutor. Along the way he fought his first duel, but neither man was injured. A temperamental man, Jackson could love or hate with committed passion.

In Nashville, Jackson boarded with a widow, Mrs. John Donelson, with whose daughter, Rachel, he fell in love. She was separated from her husband, but her courtship with Jackson provoked her husband to sue for divorce on the basis of desertion and adultery. The new couple claimed to believe that a divorce had been granted (it had not) and to have therefore married in 1791 (no record of the union survives). In September 1793 a jury found Rachel guilty and a judge granted the divorce, thus allowing Andrew and Rachel to (re)marry the following January. The full circumstances of Jackson’s marriage are not known to this day, but the incident created much controversy during his political career.

The Donelson family into which Jackson had married were one of the most prominent in Tennessee, and that connection aided his rise in Tennessee politics. In addition, he had accumulated a solid record as prosecuting attorney, and his tall frame, piercing eyes, and shock of hair cast him as an imposing presence. In 1795 Jackson won election as a delegate to the state constitutional convention. After statehood (June 1, 1796), voters chose him as Tennessee’s only representative in the U.S. House. In early 1797 the state legislature elevated him to the U.S. Senate, but he resigned the next year, uncomfortable with the grandeur of the Senate and eager to sit on Tennessee’s highest judicial body, the superior court. He was elected easily to that post and served six years as state judge.

Shortly after he had moved to Tennessee, Jackson became a land speculator in order to get rich quick. At first, his schemes almost landed him in debtors’ prison, leading to a lifelong abhorrence of debt, but he was able to purchase the "Hermitage" plantation in 1804. He established a successful trading enterprise that did business over a wide area, from Philadelphia to New Orleans. He engaged in several more duels, one, against former Tennessee governor John Sevier, ended with neither man injured; but in 1806, Jackson killed a man, Charles Dickinson, over a horse-race bet. A bullet from the latter duel remained lodged in Jackson’s chest for the rest of his life. In 1813 he was also shot in a gunfight against Jesse and Thomas Hart Benton, and that bullet was not removed until Jackson was president.

In May 1805 U.S. Vice President Aaron Burr stayed at Jackson’s Hermitage for a few days and discussed his plans against the Spanish in the Southwest and Florida. Jackson promised to provide the vice president with boats for his venture. President Thomas Jefferson believed that Burr was conspiring to create a separate nation and so charged his vice president with treason. Jackson considered Burr innocent, but the Tennesseean’s involvement was raised as a political issue when he ran for president.

At the onset of the War of 1812, Jackson was assigned by the Tennessee governor to fight the Creek Indians, British allies, on the southern frontier. He proved to have excellent military leadership skills, and his men affectionately nicknamed him "Old Hickory." He defeated the Creeks at Horseshoe Bend, then forced them to accept a harsh treaty depriving them of 23 million acres of land (about 1/5 of Georgia and 3/5 of Alabama). Afterwards, he was promoted to major-general.

Next, Jackson gathered a large force to defend New Orleans against a planned British invasion. In a spectacular victory, the Americans held the city, losing only about a dozen casualties, while around 2,000 British were killed, wounded, or captured. The battle took place after the Treaty of Ghent which ended the war had been signed. But word of the American triumph at New Orleans spread throughout the country before news of the treaty arrived from Europe. Such fortuitous timing made it seem like Jackson’s victory had brought the war to a triumphant conclusion. Although that general perception was misinformed, the battle was still highly important, since the British might have repudiated the treaty if they had captured New Orleans. Consequently, the Battle of New Orleans made Jackson an American hero, and he would remain incredibly popular for the rest of his life.

In December 1817 President James Monroe authorized a military campaign against the Seminole Indians who had been crossing the border from Spanish Florida to raid settlements in Georgia and Alabama. General Jackson, who had gained a reputation as a fierce Indian-fighter, was placed in charge of the mission. He not only defeated the Seminoles but seized Spanish Florida, executed two British subjects for aiding the Seminoles, and deported the Spanish governor and his troops to Cuba. Most of Monroe’s cabinet wanted the administration to repudiate Jackson, but Secretary of State John Quincy Adams defended him and used the American military success to negotiate the Adams-Onís Treaty of 1819. In it, Spain sold Florida to the U.S. for $5 million, and gave up claims on the Oregon Territory while recognizing America’s Louisiana Territory as extending to the Pacific Coast. In June 1821 Jackson resigned from the army to accept Monroe’s appointment as Florida’s territorial governor. He was effective in a difficult transitional period, but within a few months (November) he resigned in exhaustion and returned to Tennessee.

Urged on by many supporters, Jackson decided to run for the presidency. In July 1822 the Tennessee legislature endorsed his presidential candidacy, then in October 1823 elected him to the U.S. Senate to boost his chances for the nation’s highest office. In the 1824 race Jackson faced three other presidential candidates: Secretary of State John Quincy Adams, Speaker of the House Henry Clay, and Secretary of the Treasury William Crawford. (A fifth candidate, John C. Calhoun, had dropped out of the race to run unopposed for vice president.) Although Jackson received a plurality of the electoral and popular votes, no candidate had a majority of the electoral college, so the U.S. House was constitutionally mandated to decide the election between the top three candidates—Jackson, Adams, and Crawford. Clay endorsed Adams, who was duly selected by the House, then the new president appointed Clay as his secretary of state. Jackson and his supporters were furious and charged that there had been a "corrupt bargain."

Jackson resigned from the Senate and returned to Tennessee to begin campaigning for the 1828 presidential election. In the process, he and his key supporters, especially Martin Van Buren, formed a political organization that became known as the Democratic party. The 1828 campaign was hard-hitting, with Jackson’s opponents raising the personal issues of his allegedly-adulterous marriage, dueling, Burr conspiracy participation, rabble-rousing, and lack of political experience. But Jackson won by a landslide with 56% of the popular vote and 178 (or over 68%) of the electoral college total. His wife Rachel died unexpectedly of a heart attack the next month, and Jackson blamed his political opponents for her death.

Jackson presided (1829-1837) over an America that was rapidly changing. The ongoing market revolution was underwriting tremendous economic expansion and transformations, the institutions and attitudes of mass democracy were spreading, and numerous reform movements were vying for influence. Although Jackson did not have a role in or even approve of all the changes, he came to symbolize that dynamic era, especially the increasing democratization of politics. His administration sought to open government employment to all citizens under the concept of rotation in office and the patronage system, which detractors labeled as the "spoils" system. The Jackson administration cut back on federal expenditures to retire the $60 million national debt, which it accomplished in 1835 with help from larger tariff revenues.

Jackson invigorated executive power in a number of ways. He wielded the veto power more than all previous presidents combined, was the first president to use a pocket veto, and the first to veto a bill for non-constitutional reasons. During the "Nullification Crisis" of 1832-1833, Jackson sent federal troops to South Carolina, which was threatening to secede from the Union because of the federal government’s high tariff policy. Although he was a Southerner who was sympathetic to their plight, the president was an ardent nationalist who forcefully denied a state’s right to nullify a federal law or to secede from the Union. South Carolina backed down and Congress revised the tariff downward on a gradual basis. Jackson also took firm control of the Democratic party, dictating the party’s nomination in 1836 of his preferred successor, Martin Van Buren.

In 1832 Jackson vetoed a bill rechartering the National Bank because he considered the institution to be unconstitutional and elitist. His veto became an issue in the presidential campaign of 1832 in which Jackson won reelection by a landslide over Senator Henry Clay. Since the current National Bank charter would not expire until 1836, the president hastened the institution’s demise by withdrawing federal monies from it and depositing them in select state banks, which critics called "pet" banks. In response, Clay convinced the U.S. Senate to censure the president for that action (the censure was expunged from the record three years later).

The worst legacy of the Jackson administration was the forced removal of thousands of American Indians from their tribal homelands. Several Southern states desired the fertile lands of what were called the Five Civilized Tribes—Creeks, Cherokees, Choctaws, Chickasaws, and Seminoles. In 1830, with Jackson’s approval, Congress passed the Indian Removal Act which allocated federal funds to pay the expenses of negotiating treaties with tribes and relocating them west of the Mississippi River. During the eight years of the Jackson administration, the Senate ratified a record number of treaties with various tribes (often unrepresentative factions) and the U.S. Army removed 46,000 American Indians from their homes. The trek from Georgia and other Southern states to the new Indian Territory (now Oklahoma) was called the "Trail of Tears."