Back in 1993, an anthropologist discovered Lewis Powell's skull in a drawer and it was returned to a family member for burial in Geneva, Florida.
A fellow researcher friend of mine, Mike Kauffman has been researching the Lincoln Assassination for over 30 years. In 2004 he published "American Brutus: John Wilkes Booth and the Lincoln Conspiracies." I highly recommend it for those interested in the topic.
His spleen was notable for the granulomas caused by malaria.