In case this should prove the plan, a signal will be arranged and you duly informed, when the transports are to start with this view.

Or, it may be expedient for the boats to run past, but not the men.

In this case, then, the transports would have to be brought back to where the men could land and move by forced marches to below Grand Gulf, re-embark rapidly and proceed to the latter place.
There will be required, then, three signals; one, to indicate that the transports can run down and debark the troops at Grand Gulf; one, that the transports can run by without the troops; and the last, that the transports can run by with the troops on board.
Should the men have to march, all baggage and artillery will be left to run the blockade.
If not already directed, require your men to keep three days' rations in their haversacks, not to be touched until a movement commences.
U.S.GRANT, Major-General.
At 8 o'clock A.M., 29th, Porter made the attack with his entire strength present, eight gunboats.

For nearly five and a half hours the attack was kept up without silencing a single gun of the enemy.

All this time McClernand's 10,000 men were huddled together on the transports in the stream ready to attempt a landing if signalled.