I am wondering how many labor unions/ locals are in negotiations or have an expired contract?

I am a banquet server in Chicago; as I am discovering more and more about my union; I and other servers are working hard to get our expired contract resigned; its been a year of no negotiations. As I am also finding out the other hotels in Chicago do not have a contract either? Then just a few weeks ago my professor at school states that the teachers union at my university have been in negotiations for the last three years and they are about to strike. Now the whole issue with the Wisconsin Gov about to ban unions all together... So my theory is; that if corporations are withholding on contracts; then they can push out all the unions; get hard working employees to work harder and cheaper to make more money. So around the United states how many other unions are struggling with pay raises, work load, and getting new contracts resigned?