Abraham Lincoln appeared in "Emancipation Complication". At first, he seemed like a poor imaginary friend created to cheat. But it turned out he was really a con artist who managed to sell a lot of the imaginary friends for a hefty profit. The friends were promptly put to work doing anything they were told to do (for example, washing cars for people they were sold to). He proceeded to con Madame Foster out of the house as well. He was eventually found out and punished for his deeds.