Johnson was born on August 27, 1908 near Stonewall, Texas in a small farmhouse on the Pedernales River. His parents, Samuel Ealy Johnson, Jr. and Rebekah Baines, had three girls and two boys: Johnson and his brother, Sam Houston Johnson (1914–1978), and sisters Rebekah (1910–1978), Josefa (1912–1961), and Lucia (1916–1997).
Democratic