Key's father John Ross Key was a lawyer, a commissioned officer in the Continental Army, and a judge.
His mother Ann Phoebe Dagworthy Charlton was born February 6, 1756, to Arthur Charlton, a tavern keeper, and his wife, Eleanor Harrison of Frederick in the colony of Maryland.

Key grew up on the family plantation Terra Rubra in Frederick County, Maryland (now Carroll County).
He graduated from St. John's College, Annapolis, Maryland, in 1796 and read law under his uncle Philip Barton Key who was loyal to the British Crown during the War of Independence.
He married Mary Tayloe Lloyd on January 1, 1802.
Key's father John Ross Key was a lawyer, a commissioned officer in the Continental Army, and a judge. His mother Ann Phoebe Dagworthy Charlton was born February 6, 1756, to Arthur Charlton, a tavern keeper, and his wife, Eleanor Harrison of Frederick in the colony of Maryland.
Key grew up on the family plantation Terra Rubra in Frederick County, Maryland (now Carroll County). He graduated from St. John's College, Annapolis, Maryland, in 1796 and read law under his uncle Philip Barton Key who was loyal to the British Crown during the War of Independence. He married Mary Tayloe Lloyd on January 1, 1802.
Francis Scott Key