Authorized in fiscal year 1901 by an Act of Congress of 7 June 1900 as part of the naval buildup touched off by the Spanish–American War, the St. Louis-class cruiser initially began as an improved Olympia.

[4] One reference describes the class as "among the earliest well-documented examples of creeping growth in warship design".

The other ships of the class patrolled for German commerce raiders and escorted convoys in World War I, were decommissioned in the early 1920s, and were sold for scrap in 1930 in compliance with the London Naval Treaty.

[5] The armament of these ships was very similar to that of the concurrently-built Pennsylvania-class armored cruisers, minus the 8-inch turreted guns and the torpedo tubes.

[1][2] The engineering plant included sixteen coal-fired Babcock & Wilcox straight-tube boilers supplying 250 psi (1,700 kPa) steam to two vertical four-cylinder triple-expansion engines, totaling 21,000 ihp (16,000 kW) for 22 kn (41 km/h; 25 mph) as designed.