First Church (Charlestown) church records consist of bound volumes and loose records. Bound volumes include incorporation records; meeting minutes of the church, standing, and prudential committees; vital statistics including admissions, baptisms, members, marriages, censures, deaths, births, dismissions, and funerals; deacons' records; clerks' records; and business meeting minutes.

Loose church records include correspondence and committee reports; Sarah L. MacDonald estate papers; records of Charles P. Curtis v. The First Church in Charlestown, a dispute over the distribution of the estate of Mary D. Balfour; invitations for First Church (Charlestown) to send a pastor and a delegate to ecclesiastical councils; requests and recommendations for church membership transfers; vital statistics including births, deaths, marriages, and membership, as well as summaries of disease, age, and rainfall; and marriage certificates.

First Church treasurers' records consist of bound volumes and loose records. Bound volumes include church accounts; pew records; records of weekly contributions; and accounts of various church organizations and funds. Loose treasurers' records include treasurers' reports; church accounts; pew records and accounts; records of charitable donations; lists of church property; and correspondence.

First Church (Charlestown) Building Committee records consist of loose financial records and building plans relating to the rebuilding of the church after it was destroyed by fire in January 1957.

First Church (Charlestown) Sabbath School records contain records of the Charlestown Female Society for the Promotion of Sabbath Schools; lists of students and teachers; teachers' meeting minutes; a pamphlet commemorating the 50th anniversary of the Sabbath School; weekly Sabbath School records of attendance and donations; Sunday School secretary's records; and Pilgrim Practical Class Books.

First Church Temperance Legion records consist of a volume of meeting records and a song book.

First Church (Charlestown) printed materials consist of monthly newsletters, which include regular meeting times, messages from the minister, brief committee reports, and other church news; orders of services; pamphlets related to the First Church, including the church covenant and articles of faith, church histories, pamphlets written or edited by Rev. William Byron Forbush, and church manuals containing church histories, officers, governance, and by-laws; broadsides; clippings; laminated clippings related to the Jan. 1957 church fire; and printed ephemera.

Winthrop Church records include bound volumes and loose records. Bound volumes include church committee minutes and reports; Prudential Committee minutes; Standing Committee minutes; deacons' records; vital statistics including admissions, baptisms, and dismissions; lists of church officers, ministers, and sermons; records relating to the merger of Winthrop Church and First Church; and an index to an unidentified volume.

Loose church records consist of records of the incorporation of the Winthrop Church; reports of church committees, including the Prudential Committee and Standing Committee; clerk reports; correspondence with ministers concerning invitations to and resignations from the Winthrop Church pulpit; ecclesiastical council reports; and lists of members; as well as invitations for Winthrop Church to send a pastor and a delegate to ecclesiastical councils, and requests and recommendations for church membership transfers.

Winthrop Church treasurers' records include both bound and loose records. Bound treasurers' records include charitable accounts, pew deed records, and church account books. Loose treasurers' records consist of annual reports; warrants for the treasurer to call church meetings; accounts, including bills and receipts for goods and services including printing, fuel, water, etc.; and pew records.

Winthrop Church Building Committee records consist of reports, correspondence, and accounts, most of which relate to the subscription, location, and construction of a new meeting house. The records also include a plan of the pews of the church and the address of Rev. W. J. Budington at the laying of the cornerstone, May 31, 1848.

Winthrop Church Sabbath School records consist of bound and loose school accounts; loose school records, including reports and statistics presented by the Sabbath School Committee; a volume listing students; and teachers' reports on individual Sabbath School classes.

This subseries consists of records relating to the Winthrop Church Benevolent Association, Winthrop Choir, Ladies Sewing Circle, and Young People's Society of Christian Endeavor.

This subseries consists of weekly calendars and orders of services; issues of Winthrop's Journal, a monthly Winthrop Church publication with reports on church news and groups, clerk reports and vital statistics, sermon notes, book reviews, and advertisements; clippings; loose scrapbook pages; Winthrop Church pamphlets, including printed sermons, lists of members, and church manuals containing church histories, past officers, church governance, by-laws, and policies; and Rosamond Dayton, a volume with a Winthrop Sunday School bookplate.

One volume contains the records of Bethesda Church, Charlestown. Includes records of the founding and dissolution of the church, as well as lists of members and baptisms, 1847-1849. The Bethesda Church split off from the Winthrop Church in Feb. 1847 and dissolved 22 Mar. 1849.