CSS Louisiana
CSS Mississippi
It may be from the Genocide, but at least it's a start. Had the resources that had in OTL gone to building the
CSS Virginia gone to these ships, they might very well have been completed early enough to go into action against Farragut's forces. Also consider that having a strong fleet of Ironclads in and around New Orleans was a key part of the CSA's naval strategy up until the city's fall to Union forces. Without the distraction of the
Virginia in TTL, these ships will have considerable political backing as well as the materials available.
The effectiveness of these ships on the other hand, leaves something to be desired. If they're built to the same specifications that they were in OTL, the Battle for New Orleans will be little different. However without the need to build the
CSS Virginia figures responsible for her construction might be diverted to help with the construction of the
Louisiana and the
Mississippi.
Such as John L. Porter, John Brooke, Catesby ap Roger Jones, and William Williamson. Not to mention that without the distraction of the
Virginia Mallory himself might take a more active role in the construction of the Mississippi Ironclads (In OTL his distraction was a major source of the mismanagement). The presence of these figures might result in TTL's designs for the
Louisiana and
Mississippi being far more reasonable (more within the capability of the Confederacy to build) and far more combat effective, making them a huge problem for the Union when they try to attack in April.
One possible minor ramification of no
Virginia is the speeding up of the Peninsula campaign. Without the presence of the Confederate Ironclad, Yorktown is most likely taken in an amphibious envelopment This could have major butterflies not only on the actions of McClellan, Joe Johnson, Lee, etc, but also on Jackson and the Shenandoah. Though I'm sure eventually an ironclad would be built there, the presence of Confederate batteries guarding Richmond and the lack of available steam engines in the region probably puts the priority of having a Confederate ironclad on the Chesapeake lower than those on the Mississippi.
I think the
Monitor would still be built in OTL due to the general need for ironclads. However the dominance of designs
Monitor like designs won't occur without the climatic battle with the
Virginia. In TTL the USN will most likely stick with the more conventional casemate ironclad approach.
TTL's battles around New Orleans will also be interesting. Two properly constructed, properly manned Confederate Ironclads could make short work of the Union fleet. Given a decisive enough defeat, the Union might be forced to wait until sufficient ironclads are completed to challenge the Confederates on the lower Mississippi. Also consider that in TTL with more expertise and emphasis on naval construction on the Mississippi, work on TTL's
Arkansas and
Tennessee might be accelerated as well.