"In the matter of efficiency, I have only to refer you to the manner in which the Marines prepared for the war just past and to the manner in which they fought that war. A similar assessment for the manner in which the War Department prepared its forces for the conflict and of the manner in which its operations were conducted gives no slightest indication that an exchange of Marine specialists for soldiers would result in increased efficiency in the amphibious field. In fact, such an analysis might indicate that the country would not long remain in a position to wage amphibious warfare on the same professional basis as heretofore."
January 1, 1970
https://en.wikiquote.org/wiki/Alexander_Vandegrift