USS Nantasket. According to the Library of Congress this photo was taken between 1890 and 1901. However, a quick internet search indicates that the ship was launched in 1867 and decomissioned in the 1870s. I'm not sure if the date is wrong, if this is a different ship or a different ship with the same name, or a picture taken after the ship was sold by the US navy (though it is obviously still armed!).