This recipe comes directly from the Brown Hotel website. The following is Copied from the recipe page.
In 1923, The Brown Hotel drew over 1200 guests each evening for its dinner dance. In the "wee" hours of the morning, the guests would grow tired of dancing and retire to the restaurant for a bite to eat. Guests were growing rapidly tired of the traditional ham and eggs, so Chef Fred Schmidt set out to create something new to tempt his guests' palates. Thus, the Hot Brown was born, an open-face turkey sandwich with bacon, pimento, and a delicate mornay sauce. Who could have guessed that this chef's dedication to service would start such an enduring and well-loved Louisville tradition… the Hot Brown