Expression '... he said to a long roar'?

Please have a look at this:

"It’s been a long time coming, but tonight, because of what we did on this day, in this election, at this defining moment, change has come to America,”

I found it in an e-article about Obama’s victory, but I’m not quite sure about the meaning of the bold phrase. Does it mean that along roar of the audience came right after ‘he’ said that?

Thank you very much,

Yes, that’s correct.

It’s saying that as the speaker finished that sentence, the crowd roared (in approval).