Vehicle audio is equipment installed in a car or other vehicle to provide in-car entertainment and information for the occupants. Until the 1950s, it consisted of a simple AM radio. Additions since then have included FM radio (1952), 8-track tape players, cassette players, record players, CD players, DVD players, Blu-ray players, navigation systems, Bluetooth telephone integration and audio streaming, and smartphone controllers like CarPlay and Android Auto. Once controlled from the dashboard with a few buttons, they can be controlled by steering wheel controls and voice commands.

The Louisiana Purchase Exposition, informally known as the St. Louis World's Fair, was an international exposition held in St. Louis, Missouri, United States, from April 30 to December 1, 1904. Local, state, and federal funds totaling $15 million were used to finance the event. More than 60 countries and 43 of the then-45 American states maintained exhibition spaces at the fair, which was attended by nearly 19.7 million people.