King was born to Amelia Colbert King and Isaiah King III and grew up in the Foggy Bottom neighborhood of Washington, D.C. He attended Thaddeus Stevens Elementary School, Francis Junior High School, and Paul Laurence Dunbar High School. At Dunbar, he was a member of JROTC as well as the school's championship drill team. After graduating from high school in 1957, he earned his Bachelor of Arts degree in government from Howard University in 1961.
