Question: Are both Richard Harding Davis and Ira Levin American writers?

Context articles: The Scarlet Car
Ira Levin
The Dictator (1915 film)
Chocolate Soldier
Soldiers of Fortune (1919 film)
Stephen Steps Out
Ranson's Folly (1926 film)
Bessie McCoy
Richard Harding Davis
Bradley His Book

The Scarlet Car is a 1917 American silent drama film directed by Joe De Grasse and featuring Lon Chaney.
 The film is based upon the novel "The Scarlet Car" by Richard Harding Davis, which also was the basis of a 1923 film of the same name.
 A print of the 1917 film exists and has been released on DVD.
Ira Marvin Levin (August 27, 1929 – November 12, 2007) was an American novelist, playwright, and songwriter.
 His most noted works include the novels "A Kiss Before Dying" (1953), "Rosemary's Baby" (1967), "The Stepford Wives" (1972), and "The Boys from Brazil" (1976), as well as the play "Deathtrap" (1978).
 Many of his novels and plays have been adapted to film.
The Dictator is a 1915 American silent comedy film directed by Oscar Eagle and reputedly Edwin S. Porter.
 It was based on a play "The Dictator" by Richard Harding Davis and produced by Adolph Zukor (Famous Players Film Company) and the Charles Frohman Company.
 John Barrymore stars in a role played on the stage by William Collier, Sr. whose company Barrymore had performed in this play.
 The film was rereleased on April 13, 1919 as part of the Paramount "Success Series" of their early screen successes.
 The story was refilmed in 1922 as "The Dictator" starring Wallace Reid.
 Today the film is lost.
Chocolate Soldier is an expression referring to a good-looking but useless warrior, popularised by George Bernard Shaw's 1894 play "Arms and the Man".
 The term originates as a derogatory label for a soldier who would not fight but would look good in a uniform, shortened from 'Chocolate Cream Soldier'.
 It appears in that form in the 1897 book "Soldier of Fortune" by Richard Harding Davis.
Soldiers of Fortune is a lost 1919 American silent drama film directed by Allan Dwan and starring Wallace Beery.
 The film is based on the 1897 novel of the same name by Richard Harding Davis.
 The film was producer by the Mayflower Photoplay Company Richard Harding Davis's novel that inspired the film had already been brought to the screen in 1914 by William F. Haddock; Soldiers of Fortune had her starring Dustin Farnum.
 The subject of both the 1914 and 1919 films are based on the Spanish–American War.
 The 1919 film was shot in San Diego Fairgrounds at Balboa Park in San Diego, California.
 Distributed by Realart Pictures, the film was released in American theaters on November 22, 1919.
Stephen Steps Out is a lost 1923 American silent film that is notable as being the first starring role for the still teenaged Douglas Fairbanks, Jr..
 Directed by Joseph Henabery, it was based on a short story by Richard Harding Davis, "The Grand Cross of the Desert."
 This is a lost film.
Ranson's Folly is a surviving 1926 silent film produced by and starring Richard Barthelmess and costarring Dorothy Mackaill.
 It is based on a Richard Harding Davis novel and 1904 play, "Ranson's Folly", and was filmed previously in 1910 and in 1915 by Edison.
Bessie McCoy (1888 – August 16, 1931) was an Irish-American Vaudeville star best known for her 1908 hit song and dance routine The Yama Yama Man for which she became known as "The Yama Yama Girl".
 Her husband was the war corespondent Richard Harding Davis.
Richard Harding Davis (April 18, 1864 – April 11, 1916) was an American journalist and writer of fiction and drama, known foremost as the first American war correspondent to cover the Spanish–American War, the Second Boer War, and the First World War.
 His writing greatly assisted the political career of Theodore Roosevelt and he also played a major role in the evolution of the American magazine.
 His influence extended to the world of fashion and he is credited with making the clean-shaven look popular among men at the turn of the 20th century.
Bradley His Book (1896–1897) was an American magazine established by Will H. Bradley in Springfield, Massachusetts, in the late 19th century.
 Contributors included Richard Harding Davis, Nixon Waterman, Julia Draper Whiting, and others.
 Its visual style was unusually unified throughout the publication; "posters intended as art mingled with advertisements ... for such consumer goods as lawn sprinklers."
 Among the artists featured in the magazine were William Snelling Hadaway and Maxfield Parrish.