The Battle of Westport, sometimes referred to as the "Gettysburg of the West", was fought on October 23, 1864, in modern Kansas City, Missouri, during the American Civil War. Union forces under Major General Samuel R. Curtis decisively defeated an outnumbered Confederate force under Major General Sterling Price. This engagement was the turning point of Price's Missouri Expedition, forcing his army to retreat. The battle ended the last major Confederate offensive west of the Mississippi River, and for the remainder of the war the United States Army maintained solid control over most of Missouri. This battle was one of the largest to be fought west of the Mississippi River, with over 30,000 men engaged.

Price's Missouri Expedition, also known as Price's Raid or Price's Missouri Raid, was an unsuccessful Confederate cavalry raid through Arkansas, Missouri, and Kansas in the Trans-Mississippi Theater of the American Civil War. Led by Confederate Major General Sterling Price, the campaign aimed to recapture Missouri and renew the Confederate initiative in the larger conflict.