The most common reason settlers would gather their covered wagons into a big circle at night was to ensure a safe place to eat and sleep. This arrangement provided protection and security by creating a barrier against potential threats such as wild animals or attacks from Native American tribes. The circle formed by the wagons also served as a defensive position, allowing settlers to quickly react and defend themselves if necessary. Additionally, gathering the wagons in a circle could provide some level of shelter from the wind, making it easier to start a fire and keep it going.