I thought that Tom might have made an error using the phrase "Mr Lincoln" since I recall news broadcasts saying "President Obama" after he had left office, but it turns out for positions only held by one person at a time, the proper way to address the former president is by the last title they had before they were the president.  "You do hear it in the media where they have a need to identify politicians," but you won't see former presidents so addressed in official situations where noting -- who is currently in power and who is not -- is important."  Thanks to <a href=""http://www.formsofaddress.info/FOA_president_US_former.html"">http://www.formsofaddress.info/FOA_president_US_former.html</a> for clearing that up."