His entire immediate family died during the Revolution

From The Battle of New Orleans: Andrew Jackson and America's First Military Victory by Robert V. Remini.  Page 11.

Born in the Lancaster district of South Carolina on March 15, 1767, Andrew Jackson participated in the American Revolution as a messenger boy for Colonel William R. Davie. Only thirteen at the time, he was captured by British soldiers, mutilated on the wrist and forehead, imprisoned at Camden, South Carolina, where he contracted smallpox, but later released in a prisoner exchange arranged by his mother. His entire immediate family died during the Revolution: first his older brothers, then his mother. (His father had died shortly before his birth.) His hatred of the British lasted for the remainder of his life and no doubt accounts in large measure for his fierce determination to defeat them in battle.