An outlaw is a person declared outside the protection of the law, meaning that anyone was permitted to kill them. Many such outlaws became bandits, living away from large areas of civilisation and surviving by robbing others. One common method was to lie in wait in remote areas and rob passing travellers. Such outlaws are a popular staple of Wild West stories.
A stagecoach was a covered wagon drawn by four horses, running between stations, or stages, in different towns. These were commonly used before major railways were built, and the post was sent via stagecoach.