Built in 1927 as the home of Raleigh Coal and Coke Co. general manager Ernest E. Chilson, Casa Loma was the white-stuccoed mansion of one of the state's most prominent coal barons and founder of the Black Knight Country Club. The house featured a copper roof, eighteen-inch walls, a swimming pool, and a large garden, and it overlooked the valley's sprawling company works. Chilson died in 1931. Although he had strongly opposed unionization, his heirs sold the home to the United Mine Workers of America in 1949. After serving as district headquarters, it was repurposed as a health services, union benefits, and miner training center, and other union locals have maintained offices there over the years, giving rise to the popular name Casa Loma-Union Square.