In most states, the marriage would be VOIDABLE, not void. Most likely, you still need to get a divorce.
Or an annulment.
I edited my original post to be more clear. In answer to your question, what I meant was that my marriage to him was never valid, was it? And since I didnt have it annulled are we legally married ? I just assumed it was void since he was still married and that my legal status was unchanged, I remained single.
OK, first - a netiquette issue. It's better to add your changes in a response rather than editing your original post. Now, some of the responses to your original post may not make any sense.
That aside, you have what is called a "Voidable" marriage. it is not automatically void, but rather can be voided (assuming that you have proof that he was married at the time you married him). In addition, there are exceptions. For example, if first marriage was 1995 and then he married you in 2000 and then divorced first wife in 2002, you might no longer be able to void the marriage. Waiting that long without doing anything might make your marriage valid - requiring you to get a divorce rather than an annulment.
Furthermore, there might be reasons why you should get a divorce rather than an annulment. If you have accumulated property which is in his name, then if you get an annulment, you might lose any rights to that. If you get a divorce, you might receive 1/2 of the marital portion of the property.
Take the documentation you have to your attorney and see whether he thinks you should get an annulment or a divorce.
One thing is clear, though. Do NOT marry someone else until you get this situation sorted out.