The Civil War saw a lot of dumb decisions made on each side, but General Ambrose Burnside was probably the biggest ninny in the Union. His list of failings is lengthy, but some notable ones include sending troops across a bridge over a river where Confederate snipers could take them out at leisure despite the river being shallow enough to walk over. This led to defeat at the Battle of Fredericksburg. Later on, he ordered his troops into a crater for some reason and watched helplessly as Dixie gunmen congregated around the outside and slaughtered them all. This became known as the Battle of the Crater, despite not being much of a battle at all.