After serving six months in a military prison at war's end, he secured a pardon and resumed his law practice in New Orleans, where he also opposed Reconstruction.

Col. Campbell had been born in North Carolina and attended college in Chapel Hill before moving to Wilkes County, Georgia and studying law under Judge John Griffin.

In 1824, while this boy was in college, President James Monroe appointed Duncan Campbell and another man to try to buy the land of the Creek Native Americans.

[2][full citation needed] His maternal grandfather was Lt. Col. Micajah Perry Williamson (1744-1796), who was born in Isle of Wight County, Virginia and became a trusted officer serving under General Elijah Clarke during the American Revolutionary War.

Considered a child prodigy, Campbell graduated from the University of Georgia in 1825 at the age of 14, and immediately enrolled at the United States Military Academy, where he studied for three years.

[3][4] While at the United States Military Academy in West Point, New York, on December 24–25, 1826, Campbell was involved in the Eggnog Riot (also known as the "Grog Mutiny").

Thus Campbell aligned with Jackson on national policies, supporting the bank veto and condemning nullification, but he remained a moderate proponent of states' rights.

Fortunately for Campbell's law career, though, Mobile was a bustling port city that constantly generated commercial lawsuits and Spanish grant disputes.

In one such grant case, Mayor of Mobile v. Eslava (1849), Campbell revealed his states-rightist attitude and first articulated his doctrine of "original sovereignty" before the state supreme court.

In most cases, Campbell represented debtors against banks, demonstrating a Jacksonian Democratic tendency to advocate for state control of corporate development and champion the individual's economic freedom.

From 1847 to 1851, for example, Campbell joined the national debate on slavery with the publication of four essays in the Southern Quarterly Review in which he called for improved conditions for slaves and gradual emancipation.

President Millard Fillmore, a Whig, made three nominations to fill the vacancy, all of whom withdrew, declined to serve, or were not acted on by the Democratic-controlled Senate.

Arguably, Campbell's argument here, as well as in the dissenting opinions of fellow southern Justices John Catron and Peter V. Daniel, implicitly defended slavery.

[20] In his elaborate dissent, Campbell recounted the facts of the case, denied corporate citizenship yet again, and criticized the majority for expanding judicial power.

"[21] In other words, this decision bound the Supreme Court to protect corrupt corporations and legislatures against the warranted state constitutional amendments proposed by the people themselves.

Five years later, Campbell successfully persuaded the majority of the Court to agree with a narrower interpretation of the Contract Clause in the 1860 case of Christ's Church Hospital v. County of Philadelphia.

[14] Campbell concisely rejected the hospital's claim that the 1833 tax exemption was perpetual, writing, "such an interpretation is not to be favored, as the power of taxation is necessary to the existence of the State, and must be exerted according to the varying conditions of the Commonwealth.

As sectional tensions escalated in the late 1850s, the Court came to hear divisive slavery cases, including the notorious Dred Scott v. Sandford (1857).

Although Campbell believed that the Court could not determine Scott's citizenship status and refused to discuss this issue, he aligned with Taney in most other claims and offered a narrow interpretation of the Constitution.

[25] In March and April 1861, prior to the outbreak of the American Civil War, Justice Campbell served as a mediator between three commissioners representing the Confederacy (Martin Crawford, Andre B. Roman, and John Forsyth Jr.), and the Lincoln administration.

Since President Lincoln denied that secession was valid, he refused any official contact with the Confederate commissioners, but Justice Campbell was permitted in their place.

[29] On March 15, 1861, following the impassioned Senate speech of Stephen A. Douglas calling for the withdrawal of US forces from Confederate territory in order to ease tensions and prevent war, Lincoln's Secretary of State William H. Seward met with and assured Justice Campbell that Fort Sumter would be evacuated within ten days.

[30] As feared by Campbell, on April 8 Lincoln reversed course by publicly stating he intended to resupply Fort Sumter either "peacefully, or otherwise by force".

[32][page needed] Threatened with lynching and effectively banished from Alabama for his moderate views, opposition to secession, and attempt at mediation, Campbell settled in New Orleans.

[3] Justice Campbell was one of the three Confederate Peace Commissioners (along with Alexander H. Stephens and Robert M. T. Hunter), who met with Abraham Lincoln and William H. Seward in 1865 at the Hampton Roads Conference in an unsuccessful attempt to negotiate an end to the Civil War.

[30] Campbell was a member of the "Committee of One Hundred" that went to Washington to persuade President Grant to end his support of what they called the "Kellogg usurpation".

[40] During World War II the Liberty ship SS John A. Campbell was built in Brunswick, Georgia, and named in his honor.