A corn exchange is a building where merchants trade grains.
The word "corn" in British English denotes all cereal grains, such as wheat and barley; in the United States these buildings were called grain exchanges.
[1] Corn exchanges were initially held as open markets normally controlled by the town or city authorities.
Dedicated corn exchanges start appearing in the earlier part of the 18th century, increasing greatly following the repeal of the Corn Laws in 1846.
[2] They declined after the Great Depression of British Agriculture in the late 19th century.