Who developed a practical steam engine?

The first practical steam engine was developed by Thomas Newcomen and  patented by him. It was  developed around 1712 and described as an atmospheric engine. It was simply referred to as Newcomen engine.

It was considered the first steam engine to harness steam power and use it for mechanical purposes.

The Newcomen engine was so successful that it remained superior to all others for about fifty five years before it could be bettered.

The Newcomen engine was later improved by a man named James Watt who made it work more efficiently.

zoom in on the bill of rights. the other side was just as divided: some antifederalists opposed the constitution only because it lacked a bill of rights, and others opposed it on other grounds and merely used the bill of rights as an excuse to campaign against it.