"Mississippi" served with the Atlantic Fleet from 1909 to 1912, which consisted primarily of routine training operations. In 1910, she and other ships of the fleet visited Europe and in 1912, she carried marines to Cuba during civil unrest in the country. Too slow to operate effectively with the fleet, she was placed in reserve in 1912. "Mississippi" was reactivated in January 1914 for use as an aviation support ship assigned to the Naval Air Station Pensacola, and she supported flying boats during the occupation of Veracruz, Mexico in April 1914. By this time, the navy was prepared to dispose of the ship, and Greece, which had entered a naval arms race with the Ottoman Empire, sought to acquire warships as quickly as possible.