Write
what you see.
OR
What happened.
I would say that for most events we really don't know all the little details of how people stood, or how they held their drinks, or set them down, etc, etc. SO, you have creative license there.
If you are working on a line by line delivery say by, oh Abraham Lincoln.
Then you would just write it out and leave it mostly for the actor/director to figure out.
You'll then maybe want to break it into nice little sections with reasonable crowd actions. Going over to other characters reacting, so forth.