John Hipple Mitchell was a Portland lawyer and politician whose long career as a U.S. senator was overshadowed by scandal. He was convicted on charges of bribery connected to the Oregon Land Frauds in 1905, just five months before his death.

Born John Mitchell Hipple in Pennsylvania on June 22, 1835, he changed his name when he moved to Oregon in 1860. Several years later, the Oregonian reported that Mitchell made the change after he abandoned his first wife, Sarah Hoon, and fled Pennsylvania with a mistress and money stolen from his clients. He subsequently abandoned the mistress in California. The newspaper further alleged that he had not divorced Hoon before marrying his second wife, Mattie Price, in 1862.

Mitchell became Portland's city attorney in 1861 and a year later won election to the Oregon State Senate. Meanwhile, his private career flourished. In 1865, he sued Marcus Neff for outstanding legal fees. Because Neff was out of the state, Mitchell won by default and took possession of Neff's homestead claim, which he then sold to Sylvester Pennoyer. When Neff eventually returned to Oregon, he sued Pennoyer to recover his land. The case went to the U.S. Supreme Court, which found in Neff's favor. The precedent set by Pennoyer v. Neff in 1878 was a legal landmark and remains a significant decision.

During the 1873 legislative session, Mitchell broke with Republican leaders to challenge Henry W. Corbett for his U.S. Senate seat. Mitchell was successful, gathering a majority of the legislators’ support. The U.S. district attorney in Portland began investigating charges that railroad tycoon Ben Holladay had bribed state legislators to vote for Mitchell, but Attorney General George H. Williams quashed the investigation at Mitchell's request. The rift between Corbett and Mitchell would plague Oregon's Republican Party for the next three decades.

Although Mitchell lost his bid for reelection in 1878, he returned to the Senate in 1885. The following year, the Oregonian repeated the allegations of Mitchell's corruption and published love letters that Mitchell had written to his wife's sister, Carrie. Nonetheless, he served two consecutive terms in the Senate.

Mitchell's defeat in 1896 came at the hands of a political coalition led by Corbett, Jonathan Bourne, and William U'Ren. United solely by their mutual opposition to Mitchell, the three men and their supporters prevented a quorum in the Oregon legislature for the entire forty-day session. Not until a special session in the fall of 1898 did Oregon elect a new senator—Joseph Simon, a firm Corbett ally.

Mitchell returned to private practice until 1901, when he staged a dramatic comeback to win a fourth term as U.S. senator. He consolidated his power over the state's Republican Party with the election of former Attorney General Williams as Portland's mayor in 1902 and Charles W. Fulton as U.S. senator in 1903. Mitchell also installed Walter F. "Jack" Matthews as U.S. marshal in Portland. All three men were staunch Mitchell supporters.

As a senator, Mitchell was successful in steering federal appropriations to Oregon. In 1904, for instance, he secured congressional funding for a U.S. government exhibit at the Lewis and Clark Centennial Exposition and Oriental Fair. The government's recognition and participation was central to the Exposition's claim as a world's fair and contributed greatly to its success.

On December 31, 1904, a federal grand jury in Portland indicted Mitchell, charging that he had accepted a bribe from Stephen Puter in exchange for influencing the General Land Office to approve fraudulent homestead patents. Mitchell denied the charges in an emotional speech on the Senate floor. Soon afterward, his law partner and his private secretary testified against him.

The trial began three weeks after the Lewis and Clark Exposition opened and the day before Mitchell’s seventieth birthday. For two weeks, District Attorney Francis J. Heney presented evidence of his guilt. The defense attorneys, former Senator John M. Thurston of Nebraska and Alfred S. Bennett of The Dalles, reminded the jury of Mitchell's age and the recent death of his daughter, Jesse Chapman. The jury found him guilty.

Five months later, on December 8, 1905, while awaiting his appeal to the U.S. Supreme Court, Mitchell died from complications of dental surgery.