On leaving the army, at the age of twenty-three, Burr resumed his studies of the law, and was admitted to the Albany bar after brief preparation. Conscious of his talents, he soon after settled in New York, and enjoyed a lucrative practice, the rival of Alexander Hamilton, being employed with him on all important cases. He had married, in 1782, the widow of an English officer, a Mrs. Provost, a lady older than he,—with uncommon accomplishments. In 1784 he was chosen a member of the New York Legislature, and was on intimate terms with the Clintons, the Livingstons, the Van Rennselaers, and the Schuylers. In 1789 he was made Attorney-General of the State during the administration of Governor George Clinton. His popularity was as great as were his talents, and in 1791 he was elected to the United States Senate over General Philip Schuyler, and became the leader of the Republican party, with increasing popularity and influence. In 1796 he was a presidential candidate, and in 1800, being again a candidate for the presidency, he received seventy-three votes in the House of Representatives,—the same number that were cast for Jefferson. He would, doubtless, have been elected president but for the efforts of Hamilton, who threw his influence in favor of Jefferson, Democrat as he was, as the safer man of the two. Burr never forgave his rival at the bar for this, and henceforward the deepest enmity rankled in his soul for the great Federalist leader.
As Vice-President, Burr was marked for his political intrigues, and incurred the distrust if not the hostility of Jefferson, who neglected Burr’s friends and bestowed political favors on his enemies. Disgusted with the inactivity to which his office doomed him, Burr pulled every wire to be elected governor of New York; but the opposition of the great Democratic families caused his defeat, which was soon followed by his assassination of Hamilton, called a duel. Universal execration for this hideous crime drove him for a time from New York, although he was still Vice-President. But his political career was ended, although his ambition was undiminished.
Then, seeing that his influence in the Eastern and Middle States was hopelessly lost, Burr looked for a theatre of new cabals, and turned his eyes to the West, opened to public view by the purchase of Louisiana. In the preparation of his plans he went first to New Orleans, then a French settlement, where he was lionized, returning by way of Nashville, Frankfort, Lexington, and St. Louis. At the latter post he found General Wilkinson, to whom he communicated his scheme of founding an empire in the West,—a most desperate undertaking. On an island of the Ohio, near Marietta, he visited its owner, called Blennerhasset, a restless and worthless Irishman, whom he induced to follow his fortunes.