In the 1950s-1960s, homeopathic leader Allen Neiswander, MD, DHt (1914-2009) was at the forefront of an ongoing campaign to legitimize homeopathy in the United States as a specialty within conventional medicine. During this time, he served as a committee member for the American Institute of Homeopathy (AIH) which helped to make strides in homeopathy’s recognition. Neiswander remained active in the AIH, serving as a longtime editor for its journal; he also practiced homeopathy in California. Julian Winston (1941-2005) was a homeopathic collector and historian, as well as an author and editor of homeopathic publications. Along with his wife, he served as co-director of the Wellington College of Homoeopathy in New Zealand.

Hyland’s Naturals (also known as the Standard Homeopathic Company), a homeopathic products vendor, established the Neiswander Library in 2015, in cooperation with the Hyland’s Foundation. The library was built on Allen Neiswander's collection of books on homeopathy and complemented by Julian Winston’s collection of books, publications, and objects, and additional materials from Hyland’s and other donors. The collection documents homeopathic practice and study from the 1800s to the early 2000s. The Legacy Center acquired this donation after Hyland's dissolved the foundation and subsequently closed the library in 2021.