[1] Nathan King has been variously recorded to have been born in Ohio, Pennsylvania, or Ireland.

[2] In 2010, DNA testing on James's great-grandson, Martin III by 23andMe confirmed that the King's family Y-chromosome lineage originated from Ireland.

[3] King married Delia Linsey (1875–1924) in 1895, and they both worked as sharecroppers, in Henry County and Clayton County in Georgia, and then Stockbridge, Georgia where they settled and where their son, Martin Luther was born in 1899.

King struggled with alcoholism, and disapproved of his son and wife attending church.

When his son Martin became involved in an altercation with a white property owner the family went into hiding for a period.