Whom did Jimmy write a letter? What did he write to him?

Answer:  In O’ Henry’s story Jimmy Valentine, Jimmy wrote a letter from Elmore to Billy, one of his old friends who lived in St. Louis.

           After getting settled in Elmore and getting engaged with Annabel, Jimmy changed himself and left his dark criminal life completely. One day he wrote his one old friend who was also a professional safe-burglar. Jimmy told him to come at Sullivan’s place in Little Rock on Next Wednesday. He wrote that he wanted to give him his suitcase which was full of a set of a burglary tools. Jimmy also wrote him about his new life, his business and also about his would-be wife Annabel. He described her as an angel. He told that he had no lust for wealth and after getting married, he would go to West for new life.