This subseries documents Edie Windsor's life as an individual, with particular emphasis on her teen and single adult years, as well as her life after the death of Thea and later marriage to Judith Kasen-Windsor.

Early images in slide and print form and disassembled albums in this subseries date from the 1930s to early 1950s, tracing her life from a teen to young adult years. These images frequently feature friends and family, providing glimpses into life during World War II, post-War life, and Windsor's fondness for the beach and socializing. This is especially true of the images of her summers spent working in Atlantic City during the late 1940s and early 1950s. Her brief marriage to Saul Wiener (Windsor) and subsequent divorce are also documented in this subseries. Images in this subseries also illustrate her post-divorce life in New York City in the 1950s, highlighting her growing connection to the lesbian community through photographs of parties and trips with friends and romantic partners to local beach destinations. Posed portrait photographs of Windsor span from the 1960s to 2017. Images of Edie and Thea together are in Series I.C.

School materials includes Windsor's high school yearbook, report cards, class notes, and papers. College-era material consists of photographs, class schedules, and school newsletters from Rittenhouse College, as well as documents from Windsor's graduate studies at New York University and Harvard University/Radcliffe College during the 1960s.

Material related to Windsor's family includes photographs, estate documents, and correspondence for James "Jack" Schlain, Celia "Cele" Schlain, sister Delphina "Dolly", brother Edmund "Blackie", and cousins. The subseries also contains early photographs of relatives dating from the 1900s through the 1960s.

Windsor's calendars and appointment books (1960s–2017), notebooks, budget and expense reports, and personal correspondence offer insights into her daily life. Her correspondence in this subseries notably increased in volume following key events in her life that resonated with the LGBTQ+ community, including the death of Thea Spyer in 2009 and the landmark 2013 United States Supreme Court case United States v. Windsor.

Windsor's interest in health and wellness is reflected in notebooks tracking her progress with a substantial selection of anti-smoking, diet, and exercise-related print materials. Items from her later years, especially after 2013, include correspondence and photographs with her second wife, Judith Kasen-Windsor, whom she married in 2016. The subseries also includes condolence cards sent to Kasen-Windsor after Windsor's death in 2017, as well as Windsor's obituary, press clippings, and memorial service program.

This subseries documents the life of Thea Spyer, focusing primarily on her early childhood through early adulthood. There is a small amount of material on her later adult life.

There are an extensive number of images of Spyer as an only child, growing up in the Netherlands in the 1930s where her father served in the Dutch military and also owned a successful pickling business. Early images include Thea's mother, Elisabeth, who died when she was only a few years old and later her stepmother, Jetty. Due to their Jewish heritage, Thea's family was forced in the late 1930s to escape to England and then eventually the family settled in the United States. Other images in this subseries include formal portraits and candid shots of Thea from the 1940s to mid-1950s. Family travel photographs from the 1950s capture trips through Europe with her father and stepmother. Later images include a January 1965 trip to Eleuthera with Thea's then-girlfriend before she started to date Edie Windsor. Images of Edie and Thea together are in Series I.C.

Spyer's time as a Girl Scout at Camp Barree in the summer of 1947 is well-documented through brochures, photographs, and press clippings. School-related material in this subseries dates from the 1940s including class assignments, report cards, and graduation programs. Of note are concert programs from Spyer's time as a violin student in the Juilliard School of Music's Preparatory Division dating from the late 1940s to early 1950s. Her academic career is further represented through college-level class papers, correspondence, and student records from Sarah Lawrence College, the New School for Social Research, and Adelphi College.

Early family history materials feature documentation of her father Willem Spyer's Dutch military service beginning in the early 1910s, as well as notes on the broader Spyer family history, specifically photographs of her family's pickle factory in the Netherlands. A small collection of correspondence between Spyer's family dating from the 1930s while her father was serving in the Dutch military is also in this subseries.

Additional materials include Spyer's passports and citizenship papers; international driving certificate; jury summonses (with references to her multiple sclerosis); and life insurance forms and questionnaires.

Spyer's 2009 death certificate, obituary, tributes, funeral arrangements, and a digital video recording of her memorial service are also in this subseries.

This subseries documents the over four-decade long relationship of Edie Windsor and Thea Spyer, a lesbian couple whose enduring partnership and eventual marriage offers a powerful lens into LGBTQ+ life in the second half of the 20th century and early 21st century. Living together in New York City and spending summers on Long Island, Edie and Thea navigated the typical challenges of a relationship while also contending with the realities of remaining closeted in their professional lives, and also constantly adjusting to the long-term progression of Thea's multiple sclerosis. Their life together, beginning in 1965, is extensively chronicled through images and materials which illustrate their vibrant social world, centered mostly within their LGBTQ+ community, featuring decades of gatherings, vacations, celebrations, and their day-to-day lives.

Beginning in the late 1970s, Thea's slow progression of MS eventually rendered her a quadriplegic, requiring she use a wheelchair and full time care. Material in this subseries illustrates how the couple adapted to this loss of mobility through photographs and floorplans of accessibility-related renovations to their Fifth Avenue apartment and Tuckahoe Lane home, as well as manuals for mobility aids like bed and pool lifts. Notes and notebooks dating back to the 1970s through the early 2000s record reflections on Thea's diagnosis, symptoms, and care, as well as incidental documents, including jury duty summons for both women, which offer insight into how MS shaped their civic and personal lives.

This subseries documents Edie and Thea's love of the beach and the Long Island area, which started early in their relationship. Photographs of their first summer house rental together in 1966, which they nicknamed: "Mrs. Fordham's" are in this subseries. Images include beach days, visitors, and alone time together. Photographs, slides, and albums from subsequent summers, especially at their Tuckahoe Lane home purchased in 1969, capture pool parties, visitors, and holidays with friends and family. For the rest of their lives together, their summers were split, driving between New York City and Southampton. This subseries also includes a large collection of casual and posed images of Edie and Thea taken from 1965 through Thea's death in 2009. Milestone anniversary parties, often around Memorial Day at their Tuckahoe Lane home, were celebrated with fanfare even before they could legally marry. Notably, this subseries contains photographs and planning notes from their 15th, 20th, 25th, and 40th anniversaries, including a cake topper frequently reused throughout the years, created from a photograph of Edie and Thea from their 15th anniversary celebration.

This subseries also includes photographs of their 1993 domestic partnership and 2007 wedding in Toronto, Canada. At the time of their wedding, Thea was 77 and in fragile health, yet the couple's determination to be legally recognized, despite physical and bureaucratic obstacles, underscores the importance of their union. Their travel to Canada and wedding ceremony are documented in this subseries through planning documents, transportation logistics, correspondence, legal paperwork, print and digital photographs, as well as a digital video recording of the ceremony. Their New York Times wedding announcement drafts and photographs further document their public and private commitment. This subseries also contains press coverage surrounding their wedding, and later legal case through clippings and articles, including a controversial 2011 NYU Alumni Magazine cover that drew attention due to the couple's visibility as older married lesbians.

Also in this subseries are estate planning legal and financial papers, which became especially critical given Edie and Thea's marital status as a same-sex couple prior to federal marriage equality. These records include wills, trusts, correspondence, and financial reports which not only reflect the couple's proactive planning, but also laid groundwork for Windsor's pivotal Supreme Court case, United States v. Windsor.

This subseries also contains material related to the 2009 documentary by Bless Bless Productions: Edie & Thea: A Very Long Engagement, released after Thea's death. Items include festival programs and schedules; promotional posters and announcements; and a selection of digital video interview footage that the documentarians, Susan Muska and Gréta Ólafsdottir, created for Windsor.

Travel played a major role in their relationship, and this subseries includes notes and photographs from their trips, beginning with Suriname in 1965 and continuing to various European countries, St. Barths, Holland, and St. Thomas. The planning notes and correspondence in this subseries reveal, through the years, how each trip became more complex to coordinate as Thea's physical limitations increased and mobility became more difficult.

This subseries documents Edie Windsor's professional career as a computer programmer, beginning in the late 1950s, at a time when the field was predominantly male. Due to her rarity in the field, Windsor was frequently highlighted in IBM's promotional materials and newsletters as a visible example of a woman succeeding in computing. Windsor was also actively involved in professional programming and personal computer communities throughout her career.

Her academic foundation in the field is documented through her college papers and 1957 master's thesis from New York University. Her work as a technical manager at IBM from the late 1950s through the 1970s and then again in the mid-1980s is represented through memos, performance appraisals, and photographs. Windsor's participation in professional organizations is also well documented in this subseries through planning documents, publications, correspondence, and membership applications related to the International Dbase Users Group (IDBUG). In the 1980s, as personal computing became more widespread, Windsor became a founding member of the Board of Directors for the New York PC Users Group (NYPC), serving in various roles through the years. NYPC materials in this subseries include meeting minutes, reports, correspondence, and newsletters. Programs and notes from professional conferences are in this subseries, and of note is material from the 1987 National Computer Conference.

This subseries also contains records from Windsor's consulting company, PC Classics, Inc., founded in 1985. Materials include promotional brochures, programming code, correspondence, and client files. Notably, Windsor worked with several LGBTQ+ organizations to help improve their technology practices, particularly in managing mailing lists. Under PC Classics, she also developed her own accounting software for personal computers, known as Windsor's Disburse Program. Documentation for this program includes a user manual, order form, and program disk.

Windsor's prominence in the computing world is reflected in her media coverage, within 1984 articles in New York Magazine and Psychology Today, along with accompanying photographs. Additional materials include her resumes, business cards, and letterhead spanning from the late 1950s through the 1990s.

This subseries contains materials documenting the career of clinical psychologist Thea Spyer, who began practicing in institutional settings in the 1960s before establishing a private practice, which she maintained until her death in 2009. Her 1962 Ph.D. dissertation, along with professional journal articles from the 1970s, reflect her academic background and continued contributions to the field.

Materials from her work at the Institute for the Crippled and Disabled (now The International Center for the Disabled) date from the 1960s and include brochures, letterhead, newsletters, photographs, and employee evaluations, providing insight into her early career and professional environment. The subseries also includes resumes and business cards from various stages of her career, documenting her sustained involvement in clinical psychology over several decades.

This series documents Edie Windsor and Thea Spyer's involvement in a wide range of events and appearances primarily organized by LGBTQ+ and allied organizations from the 1980s to the 2010s. In the earlier years, Windsor and Spyer often attended events as supporters or community participants. As their visibility grew, particularly following their 2007 marriage, the couple was increasingly recognized for their contributions to LGBTQ+ advocacy. After the 2013 United States v. Windsor Supreme Court case decision, Windsor's event appearances increased as she suddenly became a well-known public figure in her 80s. Her rigorous schedule of events which are represented in this subseries is centered on honoring her achievements, celebrating her public advocacy, or highlighting her cultural significance. Towards the end of Windsor's life she was accompanied by her spouse Judith Kasen-Windsor, who is also active in the LGBTQ+ community. Files dated after Windsor's death document events attended by Judith, who honored and carried on Windsor's legacy through her own activism.

The majority of event and appearance files date from the 1980s though 2020s and typically include programs, schedules, invitations, speech text, press clippings, correspondence, publicity materials, print and digital photographs, and digital video event recordings.

Several of these events within the subseries span over multiple years, including the New York City Gay Pride Parade and the SAGE Awards and Dinner Gala–two organizations that were deeply important to both women. Other events of note include the East End Women for the Arts' off-Broadway show Taking Liberties; the first National Lesbian Conference (1991); and The Edie Windsor and Thea Spyer Foundation Exhibit and Fundraiser from 2021.