While practicing law in Hartsdale, New York, he began to write plays. Great Scott (1929), Give Us This Day (1933), and In Time to Come (1941) which were produced by Broadway.[7]
Koch began playwriting in the late 1920s before he started working on radio scripts.[8] In the 1930s, he worked as a writer for the CBS Mercury Theater of the Air. The work included the Orson Wellesradio dramaThe War of the Worlds (1938), which allegedly caused nationwide panic among some listeners for its documentary-like portrayal of an invasion of spaceships from Mars.[9][10] Koch later wrote a play about the panic, Invasion from Mars,[11] which was later adapted into the 1975 TV movie, The Night That Panicked America, in which actor Joshua Bryant plays Koch.[12]
After being blacklisted, Koch moved with his wife, Anne (an accomplished writer in her own right) and their family to Europe and eventually took up residence in the United Kingdom[15] with other blacklisted writers, where they wrote for five years for film and television (British television series The Adventures of Robin Hood among them) under the pseudonyms "Peter Howard"[8] and "Anne Rodney".[20] In 1956, they returned to the United States and settled in Woodstock, New York.[21] Koch sought help from high-profile lawyer Ed Williams in order to clear his name from Hollywood's blacklist. Koch was promptly removed from the blacklist,[22] and he resumed his name and continued to write plays and books and remained actively committed to progressive political and social justice causes. His last Hollywood screenplay was for The Fox in 1968.[14]
^U.S. Census, January 1, 1920. State of New York, County of Ulster, enumeration district 174, p. 8A, family 218.
^Tablet Magazine: "The Brothers Who Co-Wrote ‘Casablanca’ - Writers Julius and Philip Epstein are also forebears of baseball’s Theo Epstein" by Adam Chandler August 22, 2013
^Danca, Vincent J. (1974). An Analysis of Casablanca with an Emphasis on Five Scenes. University of Wisconsin--Madison.
^Communications, Museum of Broadcast (2004). The Museum of Broadcast Communications Encyclopedia of Radio. Fitzroy Dearborn. ISBN 978-1-57958-452-8.
^ ab"Howard Koch; Oscar-Winning Co-Writer of 'Casablanca'". Los Angeles Times. 1995-08-18. Retrieved 2022-08-21.
^Sterling, Christopher H. (2013-05-13). Biographical Encyclopedia of American Radio. Routledge. ISBN 978-1-136-99375-6.
^ abStarr, Kevin (2003-09-11). Embattled Dreams: California in War and Peace, 1940-1950. OUP USA. ISBN 978-0-19-516897-6.
^Riley, Kathleen (2005-04-27). Nigel Hawthorne on Stage. Univ of Hertfordshire Press. ISBN 978-1-902806-31-0.
^Roberts, Jerry (2009-06-05). Encyclopedia of Television Film Directors. Scarecrow Press. ISBN 978-0-8108-6378-1.
^Isenberg, Noah (2017-02-14). We'll Always Have Casablanca: The Legend and Afterlife of Hollywood's Most Beloved Film. W. W. Norton & Company. ISBN 978-0-393-24313-0.
^ abcGussow, Mel (18 August 1995). "Howard Koch, a Screenwriter For Casablanca, Dies at 93". The New York Times. p. D17.
^Frankel, Glenn (2017-02-21). High Noon: The Hollywood Blacklist and the Making of an American Classic. Bloomsbury Publishing USA. ISBN 978-1-62040-950-3.
^Robinson, Harlow (2007). Russians in Hollywood, Hollywood's Russians: Biography of an Image. UPNE. ISBN 978-1-55553-686-2.
^Dick, Bernard F. (2014-10-17). Hal Wallis: Producer to the Stars. University Press of Kentucky. ISBN 978-0-8131-5951-5.
^Birdwell, Michael E. (2000). Celluloid Soldiers: Warner Bros.'s Campaign Against Nazism. NYU Press. ISBN 978-0-8147-9871-3.
^"Howard Koch". Bard College Archives. Archived from the original on 2010-05-28. Retrieved 2010-04-08.