In 2015, geneticists analyzed the DNA of living descendants of Abraham Lincoln's mother. They expected to settle a 150-year-old debate. Instead, they found two things.
The first confirmed a secret Lincoln begged his closest friend to take to the grave.
The second was a genetic marker so rare, so unexpected, that it traced his maternal bloodline to a part of the world no one had predicted.
What they discovered didn't just rewrite Lincoln's family history. It exposed how brutally America once treated children born the "wrong" way - and revealed that everything we assumed about colonial ancestry was a lie.
