National Archives microfilm publication M1299 (117 rolls) serves as an index to Naturalization documents for courts in Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island and Vermont from 1791 to 1906. The cards are organized by state and then by name of petitioner, using the Soundex system. This index gives the name and location of the court that granted the naturalization, date of naturalization, and volume and page (or certificate) number of the naturalization record.|
Ancestry has digitized the index cards from this National Archives microfilm publication and included them in this database:
U.S. Naturalization Record Indexes, 1791-1992 (Indexed in World Archives Project) at Ancestry (requires payment) includes searchable digitized naturalization index cards from NARA Publication M1299 (Index to New England Naturalization Petitions, 1791-1906)
This publication is also available online from FamilySearch...
Index to New England Naturalization Petitions, 1791-1906
Finding US Naturalization Records - A Genealogy Guide