Kangaroo Court

The phrase is American, first appearing in print in The Mississippian on 12 January 1839, and firmly established by the early 1850s in books like Samuel Adams Hammett's 1853 A Stray Yankee in Texas. It described the improvised, often lawless courts set up in frontier mining camps and settlements, especially around the 1849 California Gold Rush, where accused claim-jumpers could be "tried" and punished on the spot. What nobody has ever pinned down is why "kangaroo" specifically. Theories point to the animal's unpredictable jumping motion, or a play on claim-jumping itself, but no source from the period explains the choice, and etymologists treat every theory as speculation.