Anne Marie ~
I'm late to the thread and can only add to the good thoughts already posted that forgiveness is for your benefit more than that of your father-in-law. He did whatever he did and he is responsible for his actions despite any justifications he may have made to himself or that others may have made for him. At the end of his life, you can treat him with kindness and put aside the hard feelings he generated, until he passes. Soon, he'll be in the hands of a loving God who's justice is perfect, unlike our very flawed human sense of justice. I hope your husband can forgive his father and try not to focus on what often amounts to wishing the man his father actually was had been something entirely different. He was what he was. He is responsible for his actions and attitudes. All you and Louie can do is make him as comfortable as possible and pray for him as his time draws to a close, as it will for us all, some day. Then, let the past go.
Congratulations on your upcoming 25th wedding anniversary. That certainly is a milestone and one you have every right to be proud of, especially today, when 'commitment' is often measured in months, not decades. I sincerely hope that day will be a joyful one for you and your husband and that you'll both let your father-in-law's passing from this life put to rest the long-held and very strong feelings of anger and resentment because they won't affect your father-in law and they won't change anything that happened. Try to let them be buried with Louie's father and move on with your lives. You guys deserve the happiness forgiveness and releasing animosity can bring. I pray that you'll find it.
Jim