The Shamrock was a hotel constructed between 1946 and 1949 by wildcatter Glenn McCarthy southwest of downtown Houston, Texas next to the Texas Medical Center. It was the largest hotel built in the United States during the 1940s. The grand opening of the Shamrock is still cited as one of the biggest social events ever held in Houston. Sold to Hilton Hotels in 1955 and operated for over three decades as the Shamrock Hilton, the facility endured financial struggles throughout its history. In 1985, Hilton Hotels donated the building to the Texas Medical Center and the structure was demolished on June 1, 1987.