Are novelists Walter Van Tilburg Clark and Billie Letts both American? 
Walter Van Tilburg Clark: Walter Van Tilburg Clark (August 3, 1909 – November 10, 1971) was an American novelist, short story writer, and educator. Billie Letts: Billie Dean Letts (née Gipson; May 30, 1938 – August 2, 2014) was an American novelist and educator.
yes