How many grand children did Abraham Lincoln have?

Yes. Robert Todd Lincoln, the only son and child to Abraham Lincoln to live past the age of 18, had 3 children; 2 daughters and 1 son.

• Mary "Mamie" Lincoln (October 15, 1869 - November 21, 1938)
• Jessie Harlan Lincoln (November 6, 1875 - January 4, 1948)
• Abraham Lincoln II "Jack" (August 14, 1873 - March 5, 1890)

Robert Todd Lincoln Beckwith, was Abraham Lincoln's great-grandson, and Jessie Lincoln's (Beckwith) youngest son, and Lincoln's last descendant. He died in December of 1985.