The Federal Bureau of Labor Statistics says that North Carolina has the lowest union density of any state in the union. Expressed as the "percentage of each State’s nonagricultural wage and salary employees who are union members," NC sits at 3.7%. (source - PDF)
This is something that North Carolina conservatives are no doubt proud of: unions are bad for profits (nevermind that they're good for people). And I fully understand that some unions have done as much as Friends of Big Business to give unions a bad rep.
But it seems to me that even if you're skeptical about the value of unions, dead last is not where you want to be on the list. A union is often the only way for the interests of workers to find representation in business decisions. Also, big businesses lobby the hell out of Congress (after all, it's their Congress too, right?) in ways that Joe SixPack can't seriously compete with on his own. It was unions who ended child labor, invented the 40 hour work week and the weekend, and played an instrumental role in bringing about free universal public education.
So why are unions so underrepresented in NC? (Part of the problem is certainly the state law forbidding state employees, including teachers, from unionizing.)