Irreplaceable documents a heartwarming story of the friendship between Howard Caldwell Sr. and his best friend Joe Ostrander during the tragic events of 1917-1919. The story emerged from personal letters between Howard Caldwell Sr. and his fiancée and then new wife Elsie Felt, the author Ginny Caldwell Hingst’s grandparents. All told this set of letters written more than 100 years ago survived seven different locations. Unfortunately, many will understand all too well the story within these pages.