In December 1784, Jackson took what little money he had and traveled seventy- five miles north to Salisbury, North Carolina, and began an internship with lawyer Spruce McCay. He moved into the town tavern, the Rowan House, and helped McCay run the office during the day. During the nights and weekends, Jackson partied up a storm unlike anything Salisbury had ever seen before. One resident wrote, "Andrew Jackson was the most roaring, rollicking, game-cocking, horse- racing, card-playing, mischievous fellow that ever lived in Salisbury." For a while, he attended a dance school and was appointed organizer of the Christmas Ball. As a prank, he invited the town's two most colorful prostitutes, who actually accepted the invitation, much to his chagrin. After a few awkward moments, the women had to be escorted from the party.

Jackson's practical jokes, easy-going manner and charisma made him a popular figure in Salisbury. However, three decades later, most citizens who could remember him were shocked when he became President–the general feeling in the town was that if Jackson could become President, anyone could. After three years in Salisbury, Jackson moved on to the law office of John Stokes, who had lost a hand in the Revolution and now had a silver knob on the limb that he would bang to emphasize a point. Under Stokes, Jackson wrapped up his informal study of the law, applied for the bar exam, and passed. A paucity of work, however, drove Jackson into employment at a friend's shop where he learned yet another trade. Over the course of his life Jackson learned many different trades, but seldom stayed long enough at any single job to master it–truly a jack of all trades.

After a year, Jackson realized that his only hope for success in the law lay westward. He finagled an appointment as prosecutor in the frontier western district of North Carolina and set out with a group of lawyer friends to bring law to the frontier. On the way, the group narrowly escaped massacre when, as the group fell asleep in a clearing, Jackson noted the number of owl hoots around them–and recognized the hoots as American Indian signals. He and his friends broke camp and traveled through the night. Unfortunately, a group of hunters found Jackson's abandoned campsite and stayed for the night. By morning, all but one hunter had been killed by the Indians.

The Indian attack was not Jackson's last brush with death on the trail west. In Jonesborough, where Jackson's party stayed for its first court session, another lawyer angered Jackson in court and Jackson challenged the lawyer to a duel–Jackson's first, but far from the last time he would throw down such a gauntlet. Thus, just after sundown, Jackson met Waightstill Avery outside of town. Seconds paced off the distance and the signal was given. Both men fired and both missed. Jackson's honor now restored, he shook hands with Avery and left.

Jackson and his friends left Jonesborough in October 1788 and embarked for Nashville–a small settlement right on the frontier. The settlement, though now seven years old and firmly established, remained hazardous. Lewis Robards, whose father-in-law had founded Nashville, took Jackson in to help protect the house from Indians.

As prosecutor, Jackson's first task was to help creditors recover their loans. By the time he had been in town a month, he had served seventy writs of delinquent debts to members of the community–earning the praise of most merchants and businessmen in the town. He found his law business taking off, and, as he was often paid in land or goods instead of cash, quickly found himself one of the largest landowners in Tennessee. In addition, Jackson argued almost half of all cases tried in the county during his first years in Nashville. Governor William Blount, who oversaw the territory, picked Jackson as attorney general of the Mero district of the territory. Jackson also began serving as judge advocate for the county militia. In return, Jackson closely aligned himself with Blount rather than with the other developing political party in the area, which was run by John Sevier.

Jackson also fell in love–with his landlord's wife. Robards had always been deeply suspicious and controlling of his wife, Rachel. He had already thrown her out of the house once for acting too friendly with another man. Robards became suspicious of Jackson, so Jackson left the house while Robards and his wife returned to Kentucky. The move saddened Rachel, who soon sent for her brothers to pick her up and return her to Nashville. Jackson answered Rachel's call, ending any doubt in Robards' mind about his wife's or Jackson's intentions.

When rumors began to circulate that Robard might return to Nashville to reclaim his wife, Rachel fled to Natchez, again accompanied by Jackson. When Jackson returned to Nashville, he heard that Robards had gotten a divorce in Virginia. Without double-checking this rumor, Jackson hurried back to Natchez and married Rachel in 1791. Adding even more scandal to the incident, Robards did not actually get a divorce until 1793, so Jackson and Rachel were forced to rewed. The incident would dog Jackson until he left politics and was a constant subject of his opponents' attacks for years to come.