I got to study with Foster at his very last Aestiva Latinitas Romae session, in 2008. (After his illness and retirement, he continued teaching in Wisconsin until last year.) He was a really amazing personality and so humble about probably knowing more Latin than any person in the twentieth century, as well as having had an inside view of decades of world events by writing several different popes' official reactions to them.
He also wrote, among other things, the Vatican ATM UI translation and the Vatican heliport dedicatory plaque.
I also studied with him at ALR but much earlier than that, after four years of Latin in high school and two years as an undergrad. Although he knew I was a Protestant, he was always gracious to me and I learned so much from him. He was famous for his advocacy of Gildersleeve's Latin Grammar and the Lewis & Short Latin Dictionary. He would accept no substitutes.
He also wrote, among other things, the Vatican ATM UI translation and the Vatican heliport dedicatory plaque.
https://www.flickr.com/photos/thrillho/2360283395 (literally 'please insert card in order to find out what to do')
https://orbiscatholicus.blogspot.com/2008/06/from-vatican-ci...
His death reminds me that he taught us to sing the "In Paradisum" Gregorian chant, which he considered very beautiful. Have a listen in his memory!
https://www.youtube.com/watch?v=S7F-N-Yd8dE