In large pot, combine sugar, Karo syrup, butter, and 1 can of
evaporated milk. Mixture should boil in about 10 minutes;
allow to boil for additional 15 minutes. Add second can of
evaporated milk, let boil for another 15 minutes. Add last can
of milk, and let boil for another 15 minutes, or until candy
reaches soft ball stage (when candy dropped in glass of cold
water forms a ball). Add vanilla and chopped nuts. Pour in
large flat pan 1 inch high (like cookie sheet), allow to cool.
Mixture should set when cool. When cool, cut into bite-sized
pieces and wrap each piece separately in wax paper. Store
in a cool place.