The following screenshots are from current play test, beginning turn Dec 2, 1861.
Grant has made himself visible the previous turn, but withdrew after suffering about 50% damage.
I envision this area being held for a bit longer by the Confederates, more of a delaying tactic to help preserve control over the upper Mississippi for as long as possible.
Eventually, the Union reinforcements will overwhelm the Confederate defenders and force their withdrawal.
The local change to New Madrid does make it easier to get Confederate units into and out of the area. Additionally it establishes a somewhat mutual dependency of New Madrid and the Island No. 10 Fort on each other. New Madrid further blocks Union gunboats proceeding down the Mississippi until it is taken.
One thing that needs further research is the "Lake" hex directly to the northwest of New Madrid. That makes the hex impassable, which may pose too great of an obstacle on any Union assault of New Madrid.
I need to verify the exact terrain northwest of New Madrid to see if this is supported, historically.
The natural barriers provided by the spring floods forced the Federals to march overland 50 miles to attack New Madrid from the west. On muddy roads in the midst of winter, this march was difficult but not impossible. On 28 February, Pope and his soldiers departed Commerce, Missouri. Upon his departure, he made a request to Halleck for gun and mortar boats to move to Columbus in preparation for his attack on New Madrid. After four days of trudging through the mud, Pope settled into camp on the outskirts of New Madrid. Out of range of the enemy guns, he assessed the Confederate fortifications. The strength of their fortifications and the four gunboats on the river behind them gave him pause. Pope made the decision to send for heavy artillery and more troops rather than risk open assault.
Yeah... thinking that hex needs to be changed to "Marsh" or "Swamp" to allow an attack from that direction.

- NewMadrid_Dec1861.jpg (87.84 KiB) Viewed 586 times

- NewMadrid_Dec1861_SLs.jpg (87.56 KiB) Viewed 586 times