Thomas Whittemore (1871-1950) was an intriguing person whose interests spanned various fields of endeavor, including teaching art history, conducting archaeological excavations, carrying out humanitarian relief, educating refugees, collecting art, and uncovering the mosaics of the church of Hagia Sophia in Istanbul. Various writers have explored discrete aspects of Whittemore's life, but the one part of his work that made his enterprises possible has yet to be studied: how Whittemore succeeded, over more than thirty years, in raising the funds he needed to carry out his projects. This research explores Thomas Whittemore as a fundraiser, particularly for Russian refugees, by examining his relationship with the Rockefeller family and its associates. Materials in the Rockefeller Archive Center help to sketch a preliminary picture of Whittemore's fundraising work in that domain after the First World War. His success was built first and foremost on his ability to immerse himself in the culture of the localities where he worked and thereby earn the trust of those whom he met. He built networks of supporters who advocated for him and introduced him to ever wider circles of people with wealth and influence. Whittemore's mix of cultural competence, personal appeal, and organizational efficiency led to long-standing relationships that served him and his work well for decades.