International timeline:

Hospitals:

Photographs of homœopathic hospitals worldwide.

Homœopaths:

 Dr Robert Séror's collection of photographs of leading homœopaths worldwide.

Hahnemann's Organon:

Hahnemann's own copy of the 5th edition of the Organon (1833) with his handwritten versions for the 6th edition (1842).

Homœopathy in Britain:

A history of homœopathy in Britain, by Peter Morrell.

Taubman Medical Library Homeopathy Collection, University of Michigan:

The Taubman Medical Library is currently scanning approximately 500 items in their homœopathy collection to make their full text available online. The collection contains items dating from the mid-1800s, including over a thousand pamphlets from the time.

Books:

Haller, John S. Jr. The History of American Homeopathy: The Academic Years, 1820-1935. New York: Pharmaceutical Products Press, 2005.

Kirschmann, Anne Taylor. A Vital Force: Women in American Homeopathy. Piscataway, NJ: Rutgers University Press, 2004.

The contribution of women to the development of homœopathy in America - women as physicians, lay healers and supporters.

Winston, Julian. The Faces of Homeopathy: The Book. An Illustrated History of the First 200 Years. USA: Great Auk Publishers, 1999.

-  A written and pictorial history of homœopathy, mainly in the USA and the UK from 1796 to 1996.

-  Includes a brief history of homœopathy in each state of the USA and in most countries, and a listing of all the homœopathic schools

   and hospitals that existed.

-  Fully illustrated with photos of many homœopaths.

There is also some archival information at Julian Winston's website.