Invented by Henry Peter Brougham and Vaux, 1st Baron and Lord Chancellor of England, a brougham was a four-wheeled horse-drawn carriage of the 1800s. It had a low body with a box seat in front for the drive. In back was seating for two or four with two doors.
In the 1930s, a brougham was a car with an open seat in front for the chauffeur and an enclosed cabin behind for the passengers.
Cadillac used the name on their Cadillac Brougham in 1916, and it would later be used on their top models throughout the 20th century.