Mayo's Fifth Division of the Atlantic Fleet, was in Tampico to protect American lives and interest. Ships at his disposal included the battleships ("Connecticut" and "Minnesota") and the cruisers ("Chester" and "Des Moines"). American interests included the Standard Oil refinery at Arbol Grande, other petroleum properties at Doña Cecilia, and associated American families and homes nearby. Although Tampico was besieged by Constitutionalist forces, relations between the US forces and Huerta's federal garrison remained amicable. Mayo's flagship, the gunboat , honored a request of the Mexican government and fired a 21-gun salute to the Mexican flag three times on 2 April. This was in commemoration of the capture of Puebla from the French in 1867 by General Porfirio Díaz. Additionally, sailors from the American gun boat and 2 cruisers, anchored off Tampico in the Pánuco River, went ashore each day to play baseball.