The Essex Junto was a small group of merchants and lawyers from Essex County, Massachusetts established in 1778.  Initially, the Essex Junto comprised a small independent group of intellectuals but eventually developed into an influential arm of the Federalist party.  They were dedicated to upholding the economic policies of Alexander Hamilton, while at the same time they opposed Jefferson's policies.  The Essex Junto, as a result of their opposition to the War of 1812, actually called the Hartford Convention in 1814.  Ironically, the Hartford Convention - a show of Federalist power - marked the end of the Federalist party as a force in American politics.

The Essex Junto owes its foundation to the political turmoil characteristic of the early years of the republic.  While it began as an independent entity, it quickly allied itself with the Federalist party, maintaining that political alignment for the remainder of its history.  The Essex Junto initially sought to exercise its political influence on the state level, playing a key role in the drafting of the Massachusetts Constitution in 1779-80.  With the Federalists coming to control the national government, the Essex Junto moved to the national stage and came to be identified more with the Federalists than as an individual entity.