He previously served as a delegate from Arkansas to the Provisional Congress of the Confederate States from 1861 to 1862.

His grandfather had acquired thousands of acres of land in the area at the end of the eighteenth century.

In 1821 when Johnson was seven, his parents moved the family to Arkansas Territory, where his father had been appointed as Superior Judge.

[1] Johnson was later sent back to Kentucky to study at the Choctaw Academy, which his uncle Richard Johnson had founded in 1825 on his farm near Georgetown, primarily to educate Choctaw boys from the Southeast in the English language and European-American culture.

The Choctaw students were at the school in the period prior to the Indian Removal in the 1830s of the "Five Civilized Tribes", but they were under pressure in the Southeast from encroaching settlers.

His uncle kept the school going into the late 1830s, after some peoples had been forcibly relocated to Indian Territory west of the Mississippi River.

His sister Juliette married Ambrose Sevier, who was later elected as US Senator from Arkansas.

Prior to the American Civil War, Johnson moved his family to Helena, Arkansas, in the Mississippi Delta, where he established his law practice.

After the outbreak of the American Civil War, he served as a delegate to the Provisional Government of the Confederate States in 1862.