The magnificent pile in the above photo, taken in 1919, is the Illinois National Guard First Calvary armory that once stood at Lake Shore Drive and Chicago.

Until now, I’d never seen images of this building. I remember its sturdy, less-embellished successor, which was demolished in the 1990s to build the Museum of Contemporary Art. But this building–a vertical and heroic structure built when the now-packed Streeterville area still had room to grow–was a revelation to me.

And there is more where that came from, courtesy of Calumet 412, a Tumblr that allows folks to post all sorts of Chicago images and ephemera. Users have shared  images from the posthumously-celebrated amateur photographers Vivian Maier and Charles Cushman, as well as Library of Congress files such as the one above.

There are video clips, ads, political cartoons and more–all telling a bit of the Chicago story. And since its a story that can’t be told without architecture, buildings are a huge part of Calumet 412. Like this honey below–care to guess what it was?

The above photo almost could be an image of the Lyric Opera’s lobby or something. Actually, it’s a 1911 photo of the Madison Street vestibule of the old Chicago & Northwestern train station. The building was wrecked in 1984 to build the Ogilvie Transportation Center.

I like the photo below, showing the rapidly fleshed-out skeleton of the John Hancock Center. With this image, you get a sense of how startling the building’s height must have been. Look at the Art Deco then-Playboy Building just to the right of the tower on the photo. When it was completed in 1929, the Holabird & Root-designed structure was quite the tall building–just five stories shorter than the city’s tallest, the Chicago Board of Trade. But in the late 1960s, there was a new giant in town. And more to come: