The facts of this case are connected with those of Peeler v. Phillips, a suit against Sylvanus Phillips for wrongful detention of a slave, and Phillips v. Peeler, a suit against Richmond Peeler for false imprisonment. The incidents surrounding Miller v. Cassidy no doubt served to strengthen Arkansas's reputation for lawlessness.

During the years of 1810, 1811 and 1812, when the cases involving Sylvanus Phillips, Richmond Peeler, James Kilgore and the slave named Sam were making their way through the courts of the Louisiana Territory, John Miller was hired as assistant counsel to Anthony Haden to represent Sylvanus Phillips as defendant in Peeler v. Phillips. In the April 1812 term of the Court of Common Pleas and Quarter Sessions, the case of Peeler v. Phillips came on for trial. Miller objected to Henry Cassidy sitting as a judge in the case. Cassidy had joined the bench at the December 1811 term. Miller objected because Cassidy had promised the security for the plaintiff's bond (and might therefore be prejudiced in the plaintiff's favor). Cassidy stepped down from the bench and the trial proceeded. The next day, the verdict was pronounced-Phillips was not guilty. Again Cassidy stepped down, and Anthony Haden moved for a new trial, which the court granted. The case was continued over until the next term, which would be in August.

According to the charges in this case, on May 10, at the Arkansas Post, Cassidy said that:

• Miller stole his table.
• Miller was a thief; he had stolen the books in Miller's library marked with Peter Walker's name from Peter Walker.
• Miller stole two deeds, each for 20,000 acres of land, from Peter Walker, which had been given to Walker by Elisha Winter.
• Miller obtained a slave named Sam (doubtless the same Sam at issue in Peeler v. Phillips) from Phillips by swindling and perjury.
• Miller stole his law license from Judge John B.C. Lucas (of the court in St. Louis).
• Miller was no regular lawyer.

Cassidy also threatened to dig up Phebe Miller's body (although he did not accuse Miller of murdering his own wife) and threatened to tie the rope around Miller's neck until Miller "owned himself" guilty of stealing, swindling and perjury.

Promptly at the August term of court, in the criminal Court of Quarter Sessions, where Judge Cassidy and three other judges were presiding, the grand jurors delivered an indictment against Henry Cassidy for "a libell against John Miller and his wife Phebe Miller." No doubt the grand jury was assisted in its deliberations by John Miller, who was the deputy Attorney General for the Arkansas District during this term, and thus responsible for prosecuting all criminal cases. Also during that term, two charges of assault and battery were filed against Cassidy, but the record book is silent as to who the victims were. (Cassidy pled guilty to the first charge and was fined $.25, and was tried and found innocent of the second charge-during the same term of court that he was presiding on the bench.) The grand jury's scrutiny did not overlook Miller, however, and returned a presentment against him for perjury and felony. His case was continued over until the next term. Since it would be difficult for Miller to prosecute himself, the court decided that Anthony Haden would handle that case during the next term. Thus, during this session of the Arkansas territorial court one of the judges was charged three times, sentenced once and tried once, and the prosecuting attorney was charged as well, but neither of them withdrew for the term.

On August 7, at the end of the August term, Henry Cassidy appeared in the Court of Common Pleas and made bond for $400 to the Government of Louisiana to keep the peace "towards the good citizens of the United States & more especially towards John Miller of the District of Arkansas."

Notwithstanding Cassidy's bond, on September 12, Miller appeared before Judge Vaugine and filed a charge for trespass on the case for libel against Cassidy, and sheriff Daniel Mooney was directed to summon him to the next term of court. In his declaration Miller set out the counts listed above. Miller must have been frustrated when the court did not meet for the next two years.

During that interim period, in 1813 Miller filed a declaration with the appeals court in St. Louis, alleging that Henry Cassidy had slandered and shot him, disabling his left side and wounding him in twenty one places. He swore in an affidavit that he could not receive a fair trial at Arkansas Post because Judge Cassidy was prejudiced, the Sheriff was related to Cassidy, the Clerk was a brother of Cassidy, and another judge, Samuel Moseley, was also prejudiced against Miller. Miller alleged $10,000 in damages. The St. Louis trial apparently never occurred. The first time the sheriff tried to serve process he looked only in St. Louis. The second time, he travelled to the Post, where he claimed Cassidy kept him off by force and arms.

Miller and Cassidy were also in conflict about the ownership of 20,000 arpents of land supposedly granted by Spain in the Winter grant. Miller claimed this land through his deceased wife, who supposedly received claims of Peter Walker, who in turn had received them through Winter. When Cassidy petitioned the Court of Common Pleas to partition the land in August, Cassidy objected that the instrument from Walker to Phebe Miller had not been proven in a court of law. Additionally, the Arkansas Post court had no jurisdiction in any case because the United States had not recognized the claim. Meanwhile, in 1813 Henry Cassidy traveled to St. Louis, where he studied law under a prominent attorney, Rufus Easton. Cassidy was admitted to the Arkansas bar in 1814.

By September of 1814, when a court resumed existence at the Arkansas Post, under the incarnation of the General Court for the County of Arkansas, it was a different institution. Instead of four lay judges, the new judge, George Bullitt, was an experienced lawyer and eminently qualified to be a judge. An outsider from Ste. Genevieve, he must have found it easier to be objective than would the former judges, members of the community with familial and business ties to most of the parties who appeared in the court.

Henry Cassidy stayed on, practicing law before the court. During this term, the two-year-old perjury and felony charge against John Miller was called and continued over until the next term. This slander suit against Henry Cassidy was discontinued by Miller. Anthony Haden acted as his attorney, and Perly Wallis represented Henry Cassidy. Miller was charged for costs. At the following term of the court in April, the court ordered that all left over suits commenced before the annexation of the District of Arkansas to the District of New Madrid be discontinued. John Miller does not seem to have practiced before the court after sustaining his injuries. He is the probable writer of a letter to the Commissioner of Lands reprinted in Carter, Territorial Papers of the United States, at volume 19, page 401.