looking again at the photos in the first link above, I can't help but think that some of them may have been "sharpened" in photoshop for the web blog.
Another reason why photoshop should be banned 😀
This was done with black and white film
http://www.loc.gov/exhibits/empire/making.html
"A single, narrow glass plate about 3 inches wide by 9 inches long was placed vertically into the camera by Prokudin-Gorskii . He then photographed the same scene three times in a fairly rapid sequence using a red filter, a green filter and a blue filter. "
It's pretty interesting, I'm curious of trying some "color" tri-x shots