Wouldn't you call yesterday's Union assault on the Vicksburg defensive works a separate engagement? It involved Grant's entire force and cost them 1,000 casualties. If it had been successful the siege would have ended right there.
I guess there were two initial assaults on Vicksburg, May 19 and again May 22, of which the second will be even more deadly for Union troops, producing 3,200 Union casualties, versus maybe 500 Confederate casualties.
Those are 2/3 of the casualties listed for the entire siege.
So I agree, will list the assaults separate from the siege itself.
