Leroy R. Willard HouseThe Leroy R. Willard House, also known as Willard Mansion, is located in Marshalltown, Iowa. The house was built in 1910 for Leroy R Willard and has been listed on the National Register of Historic Places since 1976.HistoryLeRoy Randall Willard was owner of the Marshall Oil Company. The home was designed by Charles Eckman using Edwardian Georgian architectural styles.