The origin of the phrase is not completely clear, but there are a few popular theories:
1. The Wild West:
* This theory suggests that the phrase originates from the stagecoach era in the American West.
* The shotgun rider was responsible for protecting the passengers from bandits by sitting near the front of the coach and aiming his shotgun at potential threats.
* This makes sense as the person sitting shotgun is usually seen as the "protector" in a modern car.
2. The Military:
* Another theory points to the military origins of the phrase.
* In early automobiles, the passenger seat was sometimes called the "shotgun seat" because the passenger could easily reach the car's shotgun, which was typically kept in the car.
* This theory is less likely as military vehicles of that time were primarily used for transportation and not for protection.
3. The "Shot" Function:
* This theory suggests that the phrase stems from the use of "shot" as a slang term for "a person" in the early 20th century.
* Sitting "shotgun" would then mean sitting beside the person driving, or "being the shot".
4. The "Shot in the Arm" Function:
* This theory suggests that the phrase was coined because the passenger sitting shotgun often got the "shot" (an injection) first when the car would stop for a medical checkup or at a doctor's office.
Ultimately, the true origin of the phrase is unclear, but the most likely explanation is the combination of the Wild West and military theories. The phrase "sitting shotgun" is a reminder of a time when cars were seen as a means of both transportation and protection.
It is important to note that the phrase is not always used literally nowadays. It is often used figuratively to describe someone who takes the lead, is in control, or is in a position of power.