The American minister to Chile, General Hugh Judson Kilpatrick and the U.S. naval commander John Rodgers, who was at port commanding a United States Navy squadron composed of the ironclad monitor USS Monadnock and the warships Powhatan, Tuscarora, and Vanderbilt, attempted a last-minute settlement with the Spanish admiral.

[3] Ultimately, all the attempts at mediation failed, as the chief condition of Admiral Méndez Núñez was the proper salute to the Spanish flag, the return by the Chileans of the captured schooner Covadonga and the immediate payment of a crippling indemnity.

Consequently the Spanish Admiral, notwithstanding the protest of the diplomatic corps, gave notice on March 27 to all neutrals to evacuate the city.

[7] While the Spanish were heavily criticized for attacking an unarmed city, so too was the British government for not employing its own naval force to protect the lives and property of its own nationals.

[8] James McNeill Whistler, who was on board the American ships, painted his famous "Nocturne in Blue and Gold: Valparaíso Bay" the night before the bombardment.