Not as far as we know, but all sorts of wild allegations were peddled by his political enemies.
Lincoln's first Vice President, Hannibal Hamlin, was also alleged to be a mulatto.
Abraham Lincoln was so important because he abolished SLAVERY HE WAS SO AMAZING DO YOU PEOPLE REALIZE HOW IMPORTANT HE IS I MEAN SERIOUSLY HE WAS A GREAT GUY.WELL APPRECIATED TOO!
Abraham Lincoln was an important figure in African-American history because he was the president who issued the Emancipation Proclamation, allowing all slaves to be free.