In September 1779, Eddy removed to New York City, and became a merchant, dealing mostly in imported goods which were shipped from England and Ireland by his brother Charles.
[1] Eddy had been engaged in charitable work, was elected a governor of the New York Hospital in 1793, and became interested in the reform of the penal laws.
In 1796, Eddy helped State Senators Philip Schuyler and Ambrose Spencer to draft a bill which established the penitentiary system.
When he found his company in financial trouble, he drew upon the idea first proposed by Joshua Forman (member of the New York State Assembly from Onondaga County in 1808) of building a canal, rather than trying to navigate the rivers.
On March 13, 1810, Platt presented his project for a bipartisan Canal Commission to the State Legislature, and received overwhelming support, and Eddy was appointed one of the Commissioners.