Why nuclear cruisers did not grow from the Alaska class

Why was the Alaska-class hull not used as the basis for the US nuclear-cruiser program?

Because recent missile-cruiser and Long Beach design work matched the new mission, while Alaska's gun-and-armor structure did not.

The answer emphasizes continuity in design experience: the Navy used hull forms and engineering work that were still active, rather than reaching back to the Alaska class. Alaska had been structured around heavy guns, armor, and large barbettes, while a nuclear missile cruiser distributes weight and internal volume differently. Long Beach therefore offered the more relevant starting point for the next designs. The comparison explains why similar displacement alone does not make one warship a useful parent for another.