For example, Lincoln made it a practice never to display his anger in public. Instead he would express himself in a lengthy letter to the offending party. He would then hang on to the letter and read it periodically until the anger subsided, finally disposing of it, having never mailed it. It was in this way that he could vent his feelings without giving needless offense to others, wihc would create barriers to his leadership.
Overcoming the Dark Side of Leadership, Gary L. McIntosh and Samuel D. Rima, page 151