It is my understanding President Lincoln has no descendants now living, so DNA is not helpful. However, if you are related to Nancy Hanks you are related to him. If you think you are related through the Lincolns you probably are not, as it is widely believed that Lincoln’s biological father was a man named Abraham Enloe, who had been Nancy’s employer. Enloe was a southerner and a man of higher intelligence than Thomas Lincoln, who, was just Lincoln’s stepfather. Enloe had a large family, the youngest son of whom was interviewed about this long after the president’s death. This man, Wesley Enloe, had the same long and lanky physique as the president. He said he had always known the story of Nancy Hanks being a servant in the house and falling pregnant there. This caused a difficulty in the Enloe marriage so his father sent Nancy away but paid for her to be cared for. It was also said Lincoln was given money to marry her.
Abraham Lincoln privately acknowledged this, even giving one of his Enloe nephews a commission even though he was a southerner and a democrat. Lincoln and his heirs created a different myth about his background to cover up the illegitimacy. He could not have succeeded in office if this was publicly known. The people of western North Carolina who descend from Enloe have perpetuated the story. That is DNA that should be tested.