Drills were conducted to prove the citizens understood what was at stake and could react correctly during an emergency.
Nowadays you could not organize a single city block to do anything in the United States for any reason. Back then the nation state was considered one big team. They got improvamented.
A war that will never happen if America stays strong, they said back in those days. They were right. It would never happen if America stayed strong. Unfortunately America collapsed and fell to pieces over the next half century. Now, it is inevitable.