The records and manuscripts of the United States Province contain correspondence, publications, notes, minutes, and abstracts, newspaper clippings, photographs, records, and annals produced by the Sisters from before the merger of the Groton and Fall River Provinces through to the time of the drafting of this finding aid (2020). The contents of this collection reflect the activity, ministry, and community trends within the Sisters in the late 20th and early 21st centuries, as well as their relations with other Provinces, mission work overseas, and the broader decline of Catholic education beginning in the late 1960s. The collection is arranged per the Mollette system, and reflects the organization of the community and its activities, and is divided into series primarily on a subject basis.

Series A covers foundation, including the literal foundation of the Province, writings regarding pre-merger negotiations between the Groton and Fall River Provinces, and constitutions of the Province as a whole. It is the broadest series in timescale, as it contains pre-merger documents from 1991-1999, as well as all revisions of the governing structure of the Sisters up until the present.

Series D covers relations with ecclesiastical authorities, individuals and organizations within the Roman Catholic Church but outside of the congregation and the sphere of women religious. These include the Archdioceses of Boston, Baltimore, and New York, the Dioceses of Providence and Fall River, and the Holy See in Rome.

Series E covers relations with other organizations of women religious, such as nuns, lay sisters, and associates of other orders. This series primarily focuses on relations with the Leadership Conference of Women Religious.

Series G covers general administration, the day-to-day operation and communication of the Holy Union Sisters as a whole, and the communications and involvement of the Province with the overall administration of the congregation. These materials include reports, circulars, annals, and newsletters from the General Council.

Series H covers relations with other individual provinces within the Holy Union Sisters, including correspondence (both physical and email) between leadership, grants and mission planning, and Provincial newsletters. These provinces include Argentina, Benin, Cameroon, Haiti, the Franco-Belgian, and Anglo Hibernian/Tanzanian Provinces. This section also covers communities within the congregation, such as individual convents, and their annals and correspondence.

Series J covers personnel, and includes personal information concerning individual Sisters, in addition to writings and artworks produced by Sisters and kept by the community, as well as files on deceased and former Sisters. The majority of the open content in this series is material created by individual sisters, in particular historical writing and scholarship from Srs. Grace Donovan and Rita Beaudoin.

Series K covers formation, the process of admittance and profession into the order, as well as the ongoing personal and professional development of individual Sisters and the community as a whole. This series includes information on vocation, discernment, retreats and sabbaticals, and conferences and workshops.

Series L covers spirituality, the structured worship, liturgy, theology, and charism of the community and its members.

Series M covers ministry, the activity of the Sisters outside of the congregation as directed by their charism. For the Holy Union Sisters, this ministry is primarily education, and this series contains most information, records, and publications related to the remaining schools operated or staffed by the Sisters of this Province during this period, such as the Country Day School and Nanaquaket.

Series P covers publications, the materials produced for circulation and consumption outside of the congregation. These include newsletters, announcements, jubilees, and promotional materials for the 125th anniversary of the arrival of the Holy Union Sisters in North America, as well as charitable and financial aid provided by the Province.

Series N covers associates, lay individuals of both sexes affiliated to the congregation as groups of organized supporters, and their activities and organization.

Series S covers artifacts, physical items, artwork, blueprints, maps, and architectural drawings, acquired or produced by the Sisters, such as materials relating to the Heritage House in Groton, MA.

Series Q and T cover temporalities, the financial and real estate holdings of the community and their management. This series includes insurance documentation, ledgers, accounting books, deeds and loan documentation, invoices, assessments, and fundraising reports.