The Berkshire String Quartet was an American classical chamber group founded and funded in 1916 at the height of World War I by Elizabeth Sprague Coolidge. The quartet, originally, was the Kortschak String Quartet, named for Hugo Kortschak (1884–1957), a member of the Chicago Symphony Orchestra from 1907 until 1914 (serving as assistant concertmaster from 1910 until 1914). Kortschak was a key figure in organizing the Berkshire Chamber Music Festival founded by Coolidge. The original Berkshire String Quartet disbanded sometime after 1941.