Which invention played a major role during the Industrial Revolution in the 18th century?

The ancient Romans had all of the components of the steam engine in their various factories and mills, but didn't of course combine them into one engine. Imagine if the industrial revolution had begun by 500AD 🤔

that was easy because there was a picture of an olden steam engine

Surprised there is no mention of James Watts

Steam engines were convenient and were the earliest type of engines and the predecessor of modern trains are steam locomotives and trains like the Ellerman Lines then came the diesel locomotives and trains and then electric trains like the Eurostar and The French TGV.