Indianapolis was the second of two ships in the Portland class, the third class of "treaty cruisers" constructed by the United States Navy following the Washington Naval Treaty of 1922, after the two vessels of the Pensacola class, ordered in 1926, and the six of the Northampton class, ordered in 1927.[7] Ordered for the US Navy in fiscal year 1930, Indianapolis was originally designated as a light cruiser because of her thin armor and given the hull classification symbol CL-35. She was reclassified a heavy cruiser, because of her 8-inch (203 mm) guns, with the symbol CA-35 on 1 July 1931, in accordance with the London Naval Treaty.[8]