While this falls strictly into the realm of historical speculation, I find it to be an interesting question, if only for mental recreation.
It is my opinion that while human civilization can be seen to be shaped generally by the ebb and flow of ideas and trends in society, it is greatly affected, and even radically changed, by individuals acting in their own capacity whether at a single moment in time or across a span of years. One has only to look at examples such as Alexander, Aquinas, Newton, and Hitler to see the range of impacts particular individuals have had. This idea stands in opposition to a theory of narrow historical determinism, although the occurrences of the past undeniably influence conditions and events in the future.
The 1790s were a crucial time in American history. The decades following the Revolution were the formative period of the United States. The actions of American governments post-Ratification largely determined the nature of the Union, the interpretation of the Constitution, and set the course for the American ship of state. Washington executed his office chiefly on the advice of his counselors, Adams, Jefferson, Hamilton, and Madison, among others. During this time, faction simmered. With the election of Adams, the differing philosophies of republicans and nationalists were brought to bear (Though this is not to say that each faction was a homogeneous entity whose members were wholly in agreement). During Adams’ presidency, key events include the Quasi-War with France, the Alien and Sedition acts, the Virginia and Kentucky Resolutions, the appointment of John Marshall as Chief Justice of the Supreme Court, and the Midnight Appointments
So, if Jefferson was elected as the second President of the United States in 1796, what would be different? How would a Jefferson presidency differ from an Adams presidency? How would these differences influence the course of American civilization? What would be different today?