The Gilded Age Websites
ExplorePAHistory.com maintains an image gallery for the railroad strike of 1877.
The Miller Center of Public Affairs at the University of Virginia maintains an "American President Online Reference Resource." Here you can find material on all of the presidents of the Gilded Age—briefs essays on their lives and presidencies, as well as biographical information on their cabinet officers and vice-presidents.
This site provides dozens of links to document, images, and short histories relevant to American labor history. It is particularly useful in linking other online document sources.
The American Studies Department at the University of Virginia has constructed a small site on Pullman. It includes a short history of the town, images, letters from residents, and brief biographies of critical figures in the town's history.
A very brief (10 minute) video biography of John Rockefeller, the founder of Standard Oil, is available online here.