The thirteen County class heavy cruisers built for the Royal Navy were built in three distinct sub-classes: the Kent, London and Norfolk classes. These were the only heavy 10,000 ton 8 inch gunned ships built for the Royal Navy, and served with distinction throughout WW2 in all theatres of war.
The Alaska and Guam were to be a class of six ships built for the USN during WW2, but the war ended before any more than 2 could be completed. These ships were designed as enlarged heavy cruisers to take on Light, Heavy and Battle Cruisers of the German and Japanese Navies.
The fourteen Baltimore and three Oregon City class cruisers were begun in 1940 with the growing threat of Japan, and the realisation that America would probably find itself fighting a two-ocean war.
Seven ships of the New Orleans class were built during the mid-1930s and were some of the most heavily engaged cruisers of WW2. Astoria, Quincy and Vincennes were all sunk during the night Battle of Savo Island.
The Pensacola class were the first heavy cruisers built for the USN, the first to have 8 inch guns, the first to be flush decked, and the first to have welded hulls. Despite the advances in ship design, these ships were top heavy and rolled considerably (although the rolling was reduced in a 1930's refit), the lack of freeboard forward made them very wet, shipping tons of water on the bow in rough weather.
The two Portland class cruisers were great improvements over previous US cruisers, and were fitted out as flag ships. These ships were in the thick of the action in the Pacific war from beginning to end, becoming some of the most decorated ships in the US Navy.
USS Wichita or "Witch" as she was known, was unique in that she was to be a Brooklyn class cruiser, but was completed with three 8 inch triple gun turrets like the New Orleans class being built at the same time.