Question: Which Supreme Court case focuses on the Louisiana Purchase?
About the article "Louisiana Purchase", section "Nature of sale".

Candidate passages:
Allgeyer v. Louisiana, , was a landmark United States Supreme Court case in which a unanimous court struck down a Louisiana statute on grounds that it violated an individual's "liberty to contract."
This was the first case in which the Supreme Court interpreted the word "liberty" in the Due Process Clause of the Fourteenth Amendment to mean "economic" liberty. 
Glass v. Louisiana, , was a case decided by the United States Supreme Court in 1985. 
Compagnie Francaise de Navigation a Vapeur v. Louisiana Board of Health, , was a United States Supreme Court case in which the Court held constitutional the involuntary quarantine of individuals suffering from communicable diseases. 
François Xavier Martin (March 17, 1762 – December 11, 1846), was an American jurist and author, the first Attorney General of State of Louisiana, and longtime Justice of the Louisiana Supreme Court.
Born in France, he immigrated to North Carolina before the American Revolutionary War.
He was appointed as Attorney General of the Territory of Orleans after the Louisiana Purchase; he also helped untangle layers of French and Spanish colonial law in the territory and subsequent state of Louisiana.
His legal writing and reviews of cases was important to codification of Louisiana law in the 1820s.
Likely his most well-known case in his decade as Chief Justice of the Louisiana Supreme Court was that of the freedom suit of Sally Miller, in "Miller v. Belmonti" (1845 La).
The court ruled to free Miller, a slave of obvious European descent, in part based on her appearance; the presumption was that she was "white" (European American), and the defendants had not sufficiently proved that she was enslaved.
The decision was unpopular in the South and contributed to the Louisiana Constitutional Convention's abolishing the state Supreme Court in March 1846, ending Martin's career at the age of 84.
The following day, the convention reinstated the court, but did not reappoint Martin or his five jurist colleagues. 
Snyder appealed his conviction, arguing that under "Batson v. Kentucky", the prosecution should not have been permitted to exercise its peremptory jury challenges based on race.
The Louisiana Supreme Court conditionally affirmed petitioner’s conviction, rejecting petitioner’s "Batson" claim, but remanded the case for a "nunc pro tunc" determination of petitioner’s competency to stand trial.
On remand, the trial court found that petitioner had been competent to stand trial, and the Louisiana Supreme Court affirmed that determination.
Snyder then petitioned the Supreme Court of the United States for a writ of "certiorari".
While Snyder's petition was pending, the U.S. Supreme Court decided "Miller-El v. Dretke"; as a result, they granted Snyder's petition, vacated the judgment, and remanded the case to the Louisiana Supreme Court for further consideration in light of "Miller-El".
On remand, the Louisiana Supreme Court again rejected Snyder’s "Batson" claim, this time by a vote of 4 to 3.
The U.S. Supreme Court again granted "certiorari".