Armed with a main battery of four 9.4 in (240 mm) guns in four single turrets, Capitán Prat was the first battleship in the world to be equipped with an electrical system.

Foreign navies tried to purchase the ship twice before the outbreak of wars, including an American attempt in 1898 and a Japanese offer in 1903.

Capitán Prat served in the fleet for about ten years, until she was disarmed in accordance with a treaty signed with Argentina intended to stop a naval arms race between the two countries.

[4] The ship was armed with a main battery of four 9.4 in (240 mm)/35 caliber Canet guns in single, electrically powered turrets.

Her secondary battery consisted of eight 4.7 in (120 mm) guns in four twin turrets; they were mounted on either side of the foremast and mainmast.

[2] On 22 August 1887, the National Congress of Chile passed a law authorizing the construction of new vessels to modernize the fleet.

[5][6][7] The contract for constructing the new Chilean battleship was advertised throughout the European shipyards, and was sought by British, German, and French shipbuilders.

[2][3][6] Capitán Prat received favorable reviews from contemporary naval critics, as she was seen as a prime example of combining a high speed with good armament and armor protection.

[11] She was also heralded as "the most powerful war ship possessed by any South American Government [sic] ... [and] any vessel at present in commission in the United States Navy.

[13][14] In addition to Capitán Prat, the Chilean Navy ordered two new protected cruisers and a pair of torpedo boats.

The British, concerned over the possibility of war between the two countries, mediated an agreement, which resulted in the Pactos de Mayo.

The treaty ended the expensive arms race and stipulated that both countries arrive at an agreement to balance their fleets.

[16][17] In March 1898, shortly before the outbreak of the Spanish–American War, the US Navy attempted to purchase Capitán Prat to bolster its fleet for the coming conflict with Spain.

[18] By 1903, in the prelude to the Russo-Japanese War, the Japanese government looked into purchasing Capitán Prat and the cruiser Esmeralda, along with other South American warships.