On February 18, 1817, Representative-elect Henry B. Lee (DR) of New York's 4th district died before the start of the 15th Congress, to which he'd been elected. A special election was held prior to the beginning of the first session of Congress to fill the resulting vacancy.
Special election
Tallmadge took his seat on December 1, at the start of the First Session of the 15th Congress.
References
New York's 4th congressional district special election, 1817 Wikipedia(Text) CC BY-SA