I am a great fan of the era of explosive growth that is the 1850s -- a period which might be called the original and real steampunk era. A friend of mine, Tim Moran, a recent PhD in American history, cited in his dissertation an actual poem (advertised as a folk song) from the 1850s that catches the excitement of that era:
Our Fathers gave us liberty,
But little did they dream,
The grand results that flow along
This mighty age of steam;
For our mountains, lakes and rivers,
Are all a blaze of fire,
And we send our news by lightning,
On the telegraphic wire
Jesse Hutchinson, Jr., 1850, Roude Folk Song Index 4556.
The painting, "American Progress," is by John Gast and dates from the 1870s.
Search this blog for "Beamish" for more unapologetic steampunk fandom.