The 1880s and 1890s were prosperous years for the Lemp Brewing Company and the Lemp family as Lemp beer had been distributed throughout the United States. The early 1900s, however, were not kind to the Lemp family or the brewery itself. William Lemp committed suicide in 1904 and several other family members perished from disease. Despite personal trouble, William Lemp Jr. continued to run Lemp Brewing and remained successful until the 1910s. The First World War and lack of new equipment contributed to the slow decline of the brewery. In 1919, the brewery unexpectedly closed and was sold to the International Shoe Company in 1922. After the sale, William Lemp Jr. also committed suicide.
In the twentieth century, however, there was renewed interest in the old Lemp Brewing complex as the city and a private company worked in tandem to make the complex a tourist destination. There had been plans to revitalize the brewery in the early 2000s, but these all seem to have been abandoned in favor of focus on the Lemp family mansion which yearly attracts visitors for dining and hospitality. The Lemp Brewery has also hosted a somewhat popular haunted house each year during the month of October before Halloween. The main body of the Lemp Brewery remains largely unoccupied to this day and not certain plans have yet been made to revitalized it.