Union Station, Pennsylvania Station?

Question

Why are so many train stations named "Union" or "Penn" Station?

Answer 1

The Union part may have to do with 2 railroads sharing 1 station.Pennsylvania is because the Penn. R.R. was a very large R.R. in it's day.

Answer 2

Each Penn Station, such as those in New York, Newark and Baltimore, was built by the former Pennsylvania Railroad.   Those three stations are now operated by Amtrak.

If there's a Union in the name, such as Chicago Union Station, it means that there were two or more stations that were combined at some point, typically prior to World War II, into a combined, or "Union" station.