What does Abraham Lincoln's tombstone look like?

He doesn't have a tombstone but is located in a memorial. It is was built at the time of his death and has been repaired and changed since his death. One of the largest changes was after the attempt to steal his body his casket was buried deeper and cemented in place. Here is an interesting side note that Lincoln was one of the first people in the United States to be embalmed. Embalming was just starting in 1864.