Congratulations on a fine choice. Oorah! Oorah! Not even in yet but wanting to learn history? God I love to see motivation!!
On Nov. 10, 1775 The Continental Congress commissioned Samuel Nicholas as a Captain and charged him with forming two battalions of Marines. It was felt that sailors should sail the ships, while somebody else did the fighting while knowing enough about sailing to assist the Navy while on board. So Sam, being the first commandant, went to the nearest bar, Tun Tavern, to find some boys that would be suitable and willing. He knew that then, as now, the natural habitat of Marines was a bar.
The direction of the Congress was: “That two Battalions of Marines be raised consisting of one Colonel, two Lieutenant Colonels, two Majors & other Officers as usual in other regiments, that they consist of an equal number of privates with other battalions; that particular care be taken that no person be appointed to office or enlisted into said Battalions, but such as are good seamen, or so acquainted with maritime affairs as to be able to serve to advantage by sea, when required. That they be enlisted and commissioned for and during the present war between Great Britain and the colonies, unless dismissed by order of Congress. That they be distinguished by the names of the first & second battalions of American Marines, and that they be considered a part of the number, which the continental Army before Boston is ordered to consist of”.
As far as the official mission of the Corps, it was established in the National Security Act of 1947. Rather than type it all out, here is a good history site. http://home.att.net/~jtyoung/mcl969/blank.htm
You also might enjoy here. http://www.grunt.com/
Feel free to send me an email if you’d like to know more, and best of luck to you maggot. (Get used to that term)