Looking for a Good U.S. Based Phone System

Hi guys. I'm looking for a phone system for my business, wondering if anyone had recommendations.

My requirements are simple. I'm in the U.S., and will make calls just in the U.S. The main thing is I am wondering if it's possible to have a phone system of sorts that allows for multiple phone numbers, each for a different business? I run 3 different dropship businesses, none related to eachother.

Because of that, I would like my employee to be able to recognize which business is being called and answer accordingly, ie. "Hello this is Dropship Business 1/2/ or 3"

Does anyone know of a system that would work for that? I'm hoping to not use my normal local telephone provider, but maybe something internet based (unless you have a reason not to). Something that can integrate these multiple numbers to one phone, be it a landline type phone or a cell phone or whatever. And something where while my employee is on the phone for one business, a call to another would go to a voice mail.

This is new to me... even though it's so old! I literally don't think I've touched a phone that was not a cell phone in over 10 years!

Thanks for any ideas!