Cave Johnson was born in 1793 near Springfield, Tennessee. Before attending Cumberland College and studying the law, he served in his father’s Indian-fighting regiment as a lieutenant from 1813 to 1814.

Following his service as a quartermaster, Johnson was admitted to the Tennessee bar in 1814 and was elected as prosecuting attorney for Montgomery County in 1817. In 1828, he was elected as a Jacksonian Democrat to the U.S. House of Representatives, where he served from 1829 to 1837. Johnson failed to secure reelection in 1836 but was successful in 1838; he served in the House from 1839 to 1845.

When James K. Polk was elected President of the United States in 1844, he nominated close friend and adviser Cave Johnson as his postmaster general. Johnson served in that capacity for the entire four years of the Polk administration. When he left office in 1849, he returned to Tennessee and resumed the practice of law before serving, from 1850 to 1851, as judge of the Seventh Judicial Circuit Court. Three years later, in 1854, Johnson became president of the Bank of Tennessee, a position he held for six years.

In 1860, President Buchanan nominated Johnson as a U.S. commissioner to mediate between the United States and the Paraguay Navigation Company. Johnson allied with the Confederacy during the Civil War and, because of this allegiance, was refused his seat in the Tennessee State Senate in 1866. Cave Johnson died later that year.