Bob Sheppard - seven letters?

[Fittster]

I've just come across the follow obituary:

"Bob Sheppard, the legendary public address announcer for the New York Yankees from 1951 to 2007, died on July 11th at the age of 99. He was raised in Queens and went to St. John’s University, where he won seven letters and served as senior class president, and later returned to serve as a speech professor."

Can our American correspondents explain 'seven letters'?


source

[cazzer]

My american Mrs says its school/univerity sports related.
If you play sport at University level you get a letter (apparently)
Then you get pins or summat for every year and sport you played.
So he could have played baseball for 4 years and football for 3.
This is a big deal in american universities for some reason...
I'm not sure why, I nodded off.

[Fittster]

Cheers, always good to learn something new.