George Washington Wilson art links 

Fine Arts Museums of San Francisco
Dumbarton Rock from the West

National Galleries of Scotland, Edinburgh
6 works online

San Francisco Museum of Modern Art  

The Royal Collection, London, UK
(Zoomable - look for the magnifying glass and the text "Magnify image")

Aberdeen Art Gallery and Museums, Scotland

Courtauld Institute of Art, London, UK
8 works by or related to the artist

Currier Gallery of Art, New Hampshire

Fred Jones Jr. Museum of Art at the University of Oklahoma
John Knox House, Edinburgh, ca.1880

Harvard University Art Museums, Massachusetts

McCord Museum of Canadian History, Montreal, Quebec

National Portrait Gallery, London, UK

 

University of Michigan SILS Art Image Browser

 

Answers.com reference works  
The "Art Encyclopedia" entry is from the Concise Grove Dictionary of Art (2002). The "Photography Encyclopedia" entry is from the The Oxford Companion to the Photograph (2005).

Union List of Artist Names (Getty Museum)  
Reference sheet with basic information about the artist and pointers to other references.