On this day in 1865

[Art]

The war didn't end at Appomattox because Confederacy didn't end at Appomattox. The government was on the run for a while after and the possibility of a guerilla war was actively discussed but eventually rejected, largely because Lee wouldn't go along. As long as Davis and his cabinet was out there and hadn't formally surrendered and the Confederacy still had armies in the field the war was still on. President Johnson declared the war over on May 9. generally considered the official date, but some Confederate generals did not formally surrender their armies until late June.

Holdouts happen in lots of wars. After WWII some NAZI units held out for weeks. Some Japanese units for years, some small groups and individuals for decades. Some of the Japanese weren't just hiding out but, especially in the Philippines were actually carrying out combat operations for years.