The New York City Municipal Archives has an almost unbroken set of records depicting City governance from 1653, when the city of New Amsterdam first received its charter, until 2013 when Mayor Michael Bloomberg left office. The one notable gap is from May 24, 1776 until February 10, 1784. These eight years, of course, cover an important time period because, on July 2nd, 1776 the Continental Congress declared independence from the British and the British fleet arrived in New York shortly thereafter. Researchers often wonder: “Where are the records of New York City government during the Revolutionary War? Were they destroyed?” Well the short answer is, there was no city government.
Mayor David Matthews took office on February 14, 1776. In May of 1776, the Continental Congress declared the colonies should form new governments separate from British rule. As tensions in the colony came to a boiling point, rumors of a plot to assassinate George Washington led to the arrest of several prominent Loyalists including Mayor Matthews on June 22, 1776. By August 27th, the British had driven back George Washington during the Battle of Long Island, and by September 15th, they had taken lower Manhattan, seizing what was then the whole of New York City. (Brooklyn, Gravesend, Harlem, etc. all were separate towns then.) From that day forward, New York City became the base of British operations in North America and the City was under military control. Matthews escaped from house arrest in Litchfield, Connecticut and made his way back to New York in December 1776. Although he retained the title of Mayor, his power was greatly reduced. Matthews did help run the police court, and may have been at least partly responsible for the notoriously poor treatment of patriots on the British prison ships.
During the war some towns in the present boroughs of Brooklyn, Bronx and Queens were considered Loyalist enough to return to local rule. Because New York City was considered too rebellious, the Common Council of New York was never reformulated for the remainder of the war. Mayor Matthews, wisely left town on November 25th, 1783, Evacuation Day, when the British Army departed Manhattan. Under the Confiscation Act, passed in 1779 by the New York Legislature, he was subject to summary execution if found in New York. He spent the remainder of his days in British-controlled Nova Scotia, where he died in 1800.
It would take three months from Evacuation Day for New York City to reconstitute a government. The new Mayor (James Duane) and the Aldermen did not meet in Common Council until February 10, 1784. One of the new government’s first acts was to request that the previous clerk, Augustus Van Cortlandt, deliver to the present clerk, “Robert Benson all and every [sic] the Books Records Papers Seals and all other Matters & Things appertaining to the said Office.” And then the business of government moved on as before, creating records.
Whatever records the British Army created during the intervening war years were not part of this collection.
 The record books covering 1657 and Sept. 1658 to Aug. 1659 are missing from the Dutch records for reasons unknown.
Minutes of the Common Council of the City of New York, ... v.8 (1774-1776). New York (N.Y.).