We didn't just replace battleships with carriers
There is a really interesting article from the Naval War College on how we wound up with the Carrier Strike Group.
http://www.usnwc.edu/getattachment/9fe423c2-9276-41c7-be29-04260b8a04c3/Replacing-Battleships-with-Aircraft-Carriers-in-th.aspx
We really don't seem to question WHY we have carrier strike groups...it's just something we've inherited. However, it wasn't always that way. The airplane was an important development, but doctrinally we changed the nature of warfare at sea by centering our task forces on carriers and giving them the doctrinal flexibility to utilize the entire strike group as needed. This allowed us to blunt the Japanese efforts to attack us (either via night fighting or kamikaze) and in the end, allowed the US to utterly dominate in the Pacific theater.
While doctrine is often the butt of jokes, when used correctly it can be a powerful tool for helping commanders focus more on employing forces and less on how they need to be organized. You don't want to reinvent the wheel for every engagement, and doctrine helps you to keep some things consistent while focusing your efforts on others.
If only we had something like this for our Expeditionary Strike Groups...
