There was no "Abraham Lincoln II." Abraham and Mary Lincoln had four sons, none of whom carried his exact name with a suffix:
| Son | Born | Died | Age | Cause / Notes |
|---|---|---|---|---|
| Robert Todd Lincoln | Aug 1, 1843 | Jul 26, 1926 | 82 | Only child to survive adulthood; Secretary of War, ambassador, Pullman Co. president. |
| Edward Baker Lincoln ("Eddie") | Mar 10, 1846 | Feb 1, 1850 | 3 | Likely tuberculosis (or medullary thyroid cancer). |
| William Wallace Lincoln ("Willie") | Dec 21, 1850 | Feb 20, 1862 | 11 | Typhoid fever (White House); devastated parents. |
| Thomas "Tad" Lincoln | Apr 4, 1853 | Jul 15, 1871 | 18 | Heart failure (likely); had speech impediment, learning difficulties. |
So: Abraham Lincoln had no son "Abraham Lincoln II." His grandson bore the name—and died young.