What can I do with a Certificate in Technical Writing and Professional Writing?

I am considering this certificate as a way to supplement my history degree. I was just curious what one with a certificate in technical writing and professional writing does exactly & whether or not it would be beneficial to me.
The classes are free to me, since I work at the university library. I just have to pay for the books.

At the very least it will broaden your horizons and round out your writing knowledge.
You never know when some experience or education will one day prove helpful. I've taken many classes that didn't seem to help me for a long time, and then later gave me an edge in getting work.
By the way, I've been looking for a side job in writing and see lots of positions open for techical writers. It's not what I'm looking for, but it might be good for you.