Jack L. Warner, Harry Warner, Albert Warner and Sam Warner were siblings who were born in Poland and emigrated to Canada near the turn of the century. In 1903, the brothers entered the budding motion picture business, first running a traveling show that brought movies to small towns in the Midwest and then opening a theater in Newcastle, Pennsylvania. In time, the Warner Brothers moved into film production, and would open their own studio in 1923. Warner Brothers quickly established itself as a studio with both nerve and vision; they were the first studio to enjoy major success with talking pictures and musicals, they were an early supporter of color films, they took on the censors with gangster films that dealt with violent crime in a realistic manner, and were unafraid to make movies that confronted the major issues of the day, such as racism, anti-Semitism, governmental corruption, abuses in the prison system and freedom of the press. Warner Brothers also made stars out of unconventional talents such as James Cagney, Humphrey Bogart, Edward G. Robinson, Bette Davis and Paul Muni, and hosted a cartoon studio that gave birth to Bugs Bunny, Daffy Duck, Sylvester the Cat and Elmer J. Fudd. Film historian and filmmaker Richard Schickel pays homage to the formative years of one of Hollywood's greatest entertainment empires in You Must Remember This: The Warner Bros. Story 1923-1949, a documentary that features plentiful film clips as well as the behind-the-scenes story of how the studio's great films came to be. Clint Eastwood narrates.