Zephaniah Swift (February 27, 1759 – September 27, 1823) was an eighteenth-century American writer, judge, lawyer, chief justice, congressman, law professor, diplomat and politician from Windham, Connecticut.

[1] He was also appointed secretary to Founding Father Oliver Ellsworth by President John Adams at the Treaty of Mortefontaine, in negotiations with King Joseph Bonaparte.

[11][12] In 1796, having served on a Congressional committee, he compiled and edited the first official version of "The Laws of the United States of America."

[14] After serving in Congress, Swift also resumed the practice of law in Windham and engaged in literary pursuits.

[19] Among his students were Charles J. McCurdy who became a Connecticut justice and Rufus P. Spalding who was a member of the Supreme Court of Ohio.

[22] The purpose of the mission was to attempt to peacefully resolve the undeclared Quasi War with France which arose in connection with the XYZ Affair.

[24] Arguably, the ability to secure this treaty with Napoleon in 1800 and its resulting good will opened the door to the Louisiana Purchase in 1803.

Swift's prestigious subscriber list to "A System of Law" includes President Washington, Vice President Adams, the Cabinet and half of the U.S. Supreme Court, along with James Madison, John Monroe, Aaron Burr, and other founding fathers (Edmund Randolph – First Attorney General and presenter of the Virginia Plan at the Constitutional Convention; Robert Morris – "Financier of the Revolution"; Oliver Ellsworth – future Chief Justice and presenter of the Connecticut Plan; Charles Lee – Third Attorney General) and signers of the Declaration of Independence.

"[33] He further explained that doing so "furnishes to the people more effective security for their liberty, than mere forms of government" and "checks their tendency to despotism, and restrains the baneful influence of party spirit.

He was outspoken in denouncing legislative interference with the courts, including the power to grant new trials and the setting aside of judgments.

"[36] He was an active member of the Connecticut Society for the Promotion of Freedom and Relief of Persons Unlawfully Holden in Bondage.

An address he delivered in 1791 in Hartford to the Society is credited as one of the reasons that Connecticut adopted a statute in 1792 to encourage emancipation by relieving former owners from liability to support their freed slaves.

[37] Swift supported softening criminal laws by making prisons more comfortable and by lessening the number of offenses punishable by the death penalty.

[43][Notes 1] Julia married Dr. Winslow T. Huntington, grandfather of Alice Louise, who married the son of Mayor George W. Gardner, an early business partner of John D. Rockefeller and political associate of Senator Mark Hanna, Chairman of the Republicans.