The Middlesex County Historical Society archives feature a broad spectrum of  18th- to 20th-century public records from the city of Middletown and County of Middlesex. Among the holdings are minutes of selectman's letters, court records, tax lists, town accounts, naturalization records, indentures, and census records.

Our collection of private and business papers from the 1700s to the 1900s is equally wide ranging. Highlights include diaries, journals, account books and correspondence from a diverse selection of local individuals and families; early shipping and maritime records, including custom house records; records of local clubs, organizations and schools; and military records from the Revolutionary War, Civil War and militia.

We also maintain extensive research files on many historical buildings, cemeteries, churches, businesses and local institutions.

Our genealogical information can be found in the Frank Farnsworth Starr Genealogy Collection, which has details on local families from 1650 to about 1830, and the Milo Wilcox Collection, which focuses on local people of color from the 1600s to about 1900. Additional genealogy sources include Martin L. Roberts' Chatham Families, an invaluable resource on early families from East Hampton, Portland and Middle Haddam; cemetery inscriptions to 1934; Middletown city directories from 1868 to 1970; and 19th-century maps and atlases of Middlesex County.