I think Tesla started out working for Edison, then went to Westinghouse. Edison persisted in the idea of trying to run DC over long distances in spite of Tesla's objections.
Westinghouse did screw Tesla, but he wasn't the first, not the last.
Here is a good site on Nikola Tesla: Forgotten American Scientist
Found that site a few year's back. One teacher's fight to keep the memory of Tesla alive!