There IS a wonderful book useful for dating Real Photo Postcards, but once in a while the original owner (or person who commissioned the photo) makes it easy. This giant pig slopped his last in 1913, but unlike many of his fellow porkers, was documented for all.
The book is Real Photo Postcard Guide by Roberrt Bogdan and Todd Weseloh from 2006.
Real Photo Postcard (The Dead 1913 Pig) Collection Jim Linderman
BOOK AND EBOOKS BY JIM LINDERMAN AVAILABLE HERE