Kenneth Lonergan ( born October 16 , 1962 ) is an American film director , playwright , and screenwriter . He is the co-writer of the film '' Gangs of New York '' ( 2002 ) , and wrote and directed '' You Can Count On Me '' ( 2000 ) , '' Margaret '' ( 2011 ) , and '' Manchester by the Sea '' ( 2016 ) . Lonergan is also known for his work as a playwright . His most famous plays include '' This Is Our Youth '' , '' Lobby Hero '' and '' The Waverly Gallery '' . Each also had a successful revival engagement on Broadway , which resulted in each play receiving a nomination for the Tony Award for Best Revival of a Play Lonergan earned an Academy Award nomination as Best Director for '' Manchester by the Sea '' , and was nominated for an Academy Award for Best Original Screenplay for '' You Can Count On Me '' , '' Gangs of New York '' , and '' Manchester by the Sea '' , winning for the latter at the 89th Academy Awards . He also won the BAFTA Award for Best Original Screenplay for '' Manchester by the Sea '' at the 70th British Academy Film Awards
70th British Academy Film Awards
70th British Academy Film Awards
Kenneth Lonergan