After the beginning of the construction of the Salt Lake City class, the U.S. Navy seeked to improve upon the design in several respects. Especially the Bureau of Construction & Repair felt that certainly, too much had been paid for the ten-gun 203mm battery that the Salt Lake City class mounted, while armor and sea-keeping among others had been sacrificed for that. Accordingly, it was suggested to either build a nine-gun ship mounting three triple turrets, or 
an eight-gun vessel with four twin turrets.  
        Although the Salt Lake City class as completed was badly underweight, this was not quite evident when the Northampton class was constructed, and accordingly, the three-turret ship was adopted since it was capable of saving weight. This weight and some of the built-in calculated margin of the Salt Lake City class was used to split the single boiler room of the previous class and increase the bulkheads protecting the boiler compartments, at an estimated  increase in weight of 200 tons.  
        The final pre-design scheme presented three turrets, nine guns, and a ship with higher freeboard and boiler rooms separated by a transverse bulkhead.  
        The critical desire to save weight also led to the design being stripped of another quarter inch off the belt, which was rather weak in any case. Some compensation resulted from the better compartmentalization and the added and strengthened bulkheads, which improved underwater defences. This was quite acceptable to the designers, for underwater damage seemed a more imminent threat to the safety of a heavy cruiser in the late 1920s than did cruiser gunfire against which belt armor could have been used. At the same time, however, the 
protection against destroyer gunfire was supposed to be increased so as to achieve protection against cruiser gunfire -- this, however, was not attempted in the end, as the construction margin seemed to small.  
        The Northamptons were the first to implement an important feature in using bunks instead of hammocks for all of the crew, at the expense of living room, but the reduced space needed for machinery, a result of improved oil storage, basically made up for the increased volume needed for sleeping room. This adoption of the more comfortable crew quartering was an important feature in a  peace-time, volunteer-crewed Navy.  
        The aircraft arrangements of the Salt Lake City class also were completely overhauled, giving the Northamptons enough shelter for the storage of four floatplanes in protection against splinters and main-battery blast, something the Salt Lake City class lacked.  
        The secondary armament equalled that of the earlier class with an initial outfit of four 127mm L/25 AA guns, upped in 1936 to eight, while the initial six torpedo tubes were removed.  
        Three ships, CA-26, -27, and -28, were built as division flagships, the other three as fleet flagships.  
        The war careers of these ships saw them in much fighting and taking heavy losses. These careers are omitted here; see the links to DANFS Online, below, for more information.  

Ships in class: 
Northampton, CA-26
Chester, CA-27
Louisville, CA-28
Chicago, CA-29
Houston, CA-30
Augusta, CA-31