Arba Seymour Van Valkenburgh was born on a farm near Syracuse, New York on August 22, 1862, the son of Lawrence Van Valkenburgh and Sarah Ann Seymour. After his mother died in 1869, he and his father moved to Michigan, and he attended public schools in Ypsilanti.
Van Valkenburgh then attended the University of Michigan, graduating with an A.B. degree in 1884.
Following graduation, Van Valkenburgh settled in Kansas City, Missouri, where he began reading law in the offices of Dobson, Douglas and Trimble. In 1888 Van Valkenburgh was admitted to the Missouri bar and entered into partnership with Delbert J. Haff, remaining together with Haff for the next decade.
Van Valkenburgh married Grace Elizabeth Ingold (1869–1933), daughter of William A. Ingold (1840–1919) and Frances A. Thirds (1846–1904), on September 25, 1889. Officiating at the ceremony was the Reverend John Emerson Roberts (1853-1942), pastor of All Souls Church, where the wedding occurred. For two years, Mrs. Van Valkenburgh had been the contralto soloist for that church, at that time located on the south side of Tenth Street, just west of Broadway Boulevard, in Kansas City, Missouri.
Arba Van Valkenburgh was appointed as Assistant U.S. Attorney for the western district of Missouri in June 1898.
Van Valkenburgh was appointed U.S. Attorney for that district in 1905, served until 1910.
As District Attorney he was called upon to prosecute the important "packers' rebate cases" involving Armour & Company, Swift & Company, Morris & Company, Cudahy Packing Company, and the Chicago, Burlington and Quincy Railroad in a conspiracy to defeat the tariff regulations of the Elkins Act. Beginning the prosecutions in 1905, he secured convictions in the District Court and affirmations in the Circuit Court of Appeals (153 Fed. 1) and in the U.S. Supreme Court (209 U.S. 56) These were the first cases to be carried through the courts of last resort and it was through them that the Elkins Act was properly interpreted and made effective.
On June 14, 1910, President William Howard Taft nominated Arba Van Valkenburgh served as a U.S District Judge for the Western District of Missouri.
The following cases are representative of those tried before him while on the bench of the District Court:Smith vs. Kansas City Title & Trust Company, in which the Federal Farm Loan Act was sustained and the creation of land banks held valid, this ruling being affirmed by the U.S. Supreme Court (255 U.S. 180).
Missouri vs. Holland, sustaining the Migratory Bird Treaty between the United States and Great Britain and the Act of Congress enforcing it (258 Fed. 479, affirmed 252 U.S. 416).
Chicago, Bulington & Quincy Railroad vs. United States, involving the interpretation of the Federal Safety Appliance Act (affirmed 237 U.S. 410).
United States vs. Emery, Bird, Thayer Dry Goods Company, involving the interpretation of the Federal Corporation Tax Law of 1909 (198 Fed. 242, affirmed 237 U.S. 28).
St. Joseph Railway, Light & Power Company, vs. Public Service Commissions, which defined certain important principles of valuation of public utilities and the regulation of rates by public authorities (268 Fed. 267).
During World War I Van Valkenburg presided over a number of high-profile political cases. Van Valkenburg was the presiding judge at the trial of a young syndicalist activist from Kansas City named Earl Browder for refusal to register for the draft and conspiracy to interfere with same. Browder, later the General Secretary of the Communist Party USA, was sentenced by Van Valkenburgh to two years imprisonment, which he served at Bates County Jail in Butler, Missouri and Leavenworth Penitentiary.
Van Valkenburgh was also the judge who sentenced Carl Glesser, a naturalized American citizen of German birth and publisher of the Missouri Staats-Zeitung, to five years in Leavenworth after Glesser had pleaded guilty to violating the Espionage Act for thirteen articles he had published. Glesser began serving his sentence on April 30, 1918.
Moreover, Van Valkenburgh presided over the May 1918 trial of socialist activist Rose Pastor Stokes for alleged violation of the Espionage Act through speaking against war profiteering. Although Stokes proclaimed that she had "at all times recognized the cause of our entrance into the war" and "at no time opposed the war," Stokes was found guilty at trial and Van Valkenburg delivered a draconian sentence of 10 years' imprisonment, declaring Stokes to be "part of a systematic program to create discontent with the war" and to advance the cause of revolution.
Van Valkenburgh was nominated by President Calvin Coolidge as Judge of the U.S. Court of Appeals for the Eighth Circuit on March 18, 1925. He was confirmed by the U.S. Senate and received commission that same day.
During his tenure as a Circuit Judge Van Valkenburgh participated in the decisions of more than 500 cases and wrote some 170 opinions. Important among these were:Wolf Bros. vs. Hamilton Brown Shoe Company, viewing important principles of the law of trademark and unfair competition (206 Fed. 611, affirmed 240 U.S. 251)
United States vs. Utah Power & Light Company, involving public lands and water power rights (three opinions: 209 Fed. 554; 230 Fed. 328; 242 Fed. 924).
Whitesides vs. Norton, which involved riparian rights and incidentally, the boundary line between Minnesota and Wisconsin (205 Fed. 5).
Arba Seymour Van Valkenburgh died on November 4, 1944, in Kansas City, Missouri. He and his wife did not have children. Judge Van Valkenburgh was devastated at the death of his wife, and commissioned a memorial stained glass window from the surviving Tiffany glass firm, Louis C. Tiffany Studios Corporation, for the cathedral church of the Episcopal Diocese of West Missouri, Grace and Holy Trinity Cathedral, located in Kansas City, Missouri. It was dedicated on February 3, 1935.