During his third year of law school, Hall served as President of the Cornell Legal Aid Clinic.

Hall's legal career prior to joining the federal bench was divided between the United States Attorney's Office and private practice.

Following George W. Bush's election to the Presidency in 2001, Hall returned to the federal government, this time as the United States Attorney for the District of Vermont.

President Bush nominated Hall to the Second Circuit on December 9, 2003, to fill the vacancy left by Judge Fred I. Parker.

Supported by Vermont Senators Jim Jeffords and Patrick Leahy, Hall's nomination was uncontroversial, and he was confirmed on June 24, 2004, by voice vote.