Lost Battalion

The Lost Battalion is the name given to the nine companies of the US 77th Division, roughly 554 men, isolated by German forces during World War I after an American attack in the Argonne Forest in October 1918. Roughly 197 were killed in action and approximately 150 missing or taken prisoner before the 194 remaining men were rescued. They were led by Major Charles W. Whittlesey.

On 2 October, the 77th division launched an attack into the Argonne, under the belief that French forces were supporting their left flank and two American units including the 92nd Infantry Division were supporting their right. Within the 77th sector, some units, including Whittlesey's 308th Infantry, were making significant headway.

Source: Wikipedia