This list was inspired by Pat Denault's blog post on The Exchange, the Business History Conference's blog, a few years back. It offers links to historical exhibits online, which differ from the online collections highlighted on my Virtual archives page in that they focus on a particular historical topic or theme. These exhibits tend to be temporary, so check back often. I will add new sites and remove defunct exhibits as time permits. Also, a tip from Pat Denault: keep an eye on the Smithsonian Libraries' list of Library and Archival Exhibitions on the Web.
Digital Public Library of America exhibits on the Erie Canal, American empire, Montana industries, shoe industry in Massachusetts, 1912 Bread and Roses strike, and the 1918 flu pandemic, among many other topics
The Wisconsin Historical Society's online exhibits on McCormick-International Harvester's advertising posters, the Red Dot Potato Chip Company, life in the Atomic age, Milwaukee potter Susan Frackelton, and Horlick's Malted Milk
The Maine Historical Society's Maine Memory Network exhibits on a local railroad, a furniture store, textile manufacturing, the timber mast trade, corn canning, blueberry and potato farming, colonial cartography, and a raft of other topics
University of Toledo Library's Time in a Bottle: A History of Owens-Illinois, Inc.