The 1830's, when the poem was written, can be considered to be the very beginning of modernity. The electric telegraph, the steamship and railroad were introduced about that time. People for the first time could actually see technological change occuring around them, changing their lives. The Industrial Revolution was underway, with its mass manufacturing, urbanization and all the social baggage that goes along with it.

For the preceding generations, change was something that you might be aware of if you were educated, but as far as most people were concerned, the world their grandchildren would live in was going to be pretty much the one their grandparents came from. Except for geographically or historically localized events like wars, plagues or famines, people simply didn't think in terms of "social change", especially that brought about by new technology.

As one Naval historian once put it, if Chistopher Columbus (1492) had been aboard Nelson's flagship HMS Victory at Trafalgar (1805), he would have marveled at its size and complexity, but would have had no trouble understanding how it was built, navigated, sailed and fought.

I think Tennyson was aware he lived in a time of change, and was naturally optimistic about it. Remember what Stanley Kubrick (1968)
imagined 2001 would be like?

Unfortunately, I haven't read your story yet. Can you give me a hint?