In the year after his term as District Attorney expired, Dixon earned wide recognition for his prosecution of John Baptiste DuBay in his murder trial. DuBay had been involved in a property dispute with William Reynolds, and killed him after a confrontation. DuBay was a prominent character in the Wisconsin Territory and the early years of statehood. He was a celebrated pioneer character, connected to the American Fur Company, which was one of the most powerful businesses in the Wisconsin Territory. He was part French Canadian, part Menominee Indian, and served as an interpreter for many important negotiations with Wisconsin's Native American communities. DuBay's attorneys were both esteemed lawyers and prominent politicians—Moses M. Strong had been Speaker of the Wisconsin Assembly, and had famously secured the acquittal of James Russell Vineyard after he had killed a fellow representative on the floor of the territorial legislature; Harlow S. Orton had been an attorney for Governor Coles Bashford when he successfully challenged the results of the 1855 Wisconsin gubernatorial election. The judge in the case, Wisconsin Circuit Court Judge Alexander L. Collins, gave wide deference to the defense to bring in a number of prominent Wisconsin pioneers and statesmen to testify to the character of the defendant. DuBay was ultimately acquitted, but Dixon's reputation was secure. Within a year, he would take the place of the judge who had presided over the case, and within two years he would be Chief Justice of the Wisconsin Supreme Court. Dixon later summarized that the real defendant in the trial was the "pioneer spirit," and that DuBay's crimes went unpunished due to a parade of prominent Wisconsin pioneer character witnesses, which muddied the facts of the crime.
Wisconsin judiciary
In 1858, Alexander Collins resigned his seat as Judge of the 9th Circuit. The new Governor, Alexander Randall, appointed Dixon to the seat, which had jurisdiction over Columbia, Dane, Jefferson, and Sauk counties. Less than a year later, in April 1859, Chief Justice Edward V. Whiton died suddenly. Governor Randall again turned to Dixon, naming him Chief Justice of the Wisconsin Supreme Court at the age of 33. Only months after his appointment as Chief Justice, Dixon ran into controversy when he dissented from the majority of the court which had voted to ignore the ruling of the United States Supreme Court in the case of Ableman v. Booth. The Wisconsin Supreme Court had previously ruled that the federal Fugitive Slave Act of 1850 was unconstitutional, a position which was popular with the ascendant abolitionist Republican party in Wisconsin. The Supreme Court overruled the Wisconsin Court, ruling that state courts could not annul federal laws. Dixon wrote in favor of accepting the decision of the U.S. Supreme Court, stating that while he personally believed the Fugitive Slave Act was unconstitutional, he agreed with the federal court's interpretation of their jurisdiction. His dissent resulted in him losing the support of the Republican Party for his re-election in 1860. Nevertheless, he was able to obtain re-election as an independent. And was re-elected two more times after that. Dixon resigned from the court in 1874 to return to private legal practice. He distinguished himself again in this phase, representing the State of Wisconsin in upholding the constitutionality of the state's railroad regulation "Granger" laws.
Luther Dixon married Mary Eliza Woods. They had five children together, though only four survived to adulthood. Dixon suffered from asthma and moved to Denver, Colorado, in 1879 for the health benefits, though he maintained a home in Wisconsin as well. He died in 1891 while visiting Milwaukee on his way back from a trip to Washington, D.C.
