Henry-
Yes, the letter is dated 1853. Evidently the person posting the item is viewing the individuals anachronistically speaking about their ranks historically to interest prospective bidders.
It is written by WCW jr. to a family friend while visiting his father whose ship was then in Boston. No mention that he will be going to the Academy the following year. His father WCW sr. appends a note to the addressee at the end of the letter.
If the link does not work, just go to e-Bay and use their search feature, input "1853 letter" and choose the category "Collectibles."
If all else fails I have downloaded the JPEGS and can send them to you if you contact me at my e-mail address
rwoz2@yahoo.com
Regards,

Ralph