See link: http://bodhranman.files.wordpress.com/2008/03/steampunk.jpg

Steampunk is a new name for an aesthetic that has been around for quite awhile. From the pages of Jules Verne to the modern Steampunk art movement, Steampunk seeks to capture
the wonder of the mad scientist,
the technical splendor of the celebrated machine age,
the adventurous spirit of the gentleman explorer,
and the hope of the humanist progressive.

Steampunk is very much a Victorian/Edwardian Era revival, with a modern mad twist (which is why it's so darn fun).

For reference, see the literary works of Jules Verne and such movies as The League of Extraordinary Gentlemen.