Is it a coincidence that the question of the right to own slaves in this country was concurrent with the rise of the industrial age?

we are all slaves today for Marmalade Mussolini.

No. Some of the founding fathers knew slavery was inherently wrong but they also knew that becoming very wealthy plus having the time to philosophize about government required the ownership of slaves. Cotton was the most labor-intensive which meant the invention of the cotton gin made the biggest impact on the question of slavery

Of course not. While slavery had been questioned earlier, largely in the context of the Enlightenment, the question seriously arose also in Britain with the rise of the Industrial Age there, whereas countries still heavily dependent on an agricultural economy did NOT question slavery.

It's a certainty that slavery came into being in the context of settled agriculture about 10,000 years ago.