Question: is David McCullough or Nick Hornby an American author?

Context paragraphs:
David McCullough: David Gaub McCullough ( ; born July 7, 1933) is an American author, narrator, historian, and lecturer.  He is a two-time winner of the Pulitzer Prize and the National Book Award and a recipient of the Presidential Medal of Freedom, the United States' highest civilian award.

How to Be Good: How to Be Good is a 2001 novel by the English writer Nick Hornby.  It centers on characters Katie Carr, a doctor, and her husband, David Grant.  The story begins when David stops being "The Angriest Man In Holloway" and begins to be "good" with the help of his spiritual healer, DJ GoodNews (who also shows up briefly in Hornby's "A Long Way Down").  The pair go about this by nominally convincing people to give their spare bedrooms to the homeless, but as their next scheme comes around, "reversal" (being good to people one has not been good to in the past), this proves to be fruitless and thus David gives up his strivings and his plans for a book on how to be good, appropriately named "How to be Good."

Nick Hornby: Nicholas Peter John "Nick" Hornby (born 17 April 1957) is an English novelist, essayist, lyricist, and screenwriter.  He is best known for his memoir "Fever Pitch" and novels "High Fidelity" and "About a Boy", all of which were adapted into feature films.  Hornby's work frequently touches upon music, sport, and the aimless and obsessive natures of his protagonists.  His books have sold more than 5 million copies worldwide as of 2013.  In a 2004 poll for the BBC, Hornby was named the 29th most influential person in British culture.

The Greater Journey: The Greater Journey: Americans in Paris is a 2011 non-fiction book by the Pulitzer Prize-winning author David McCullough.  In a departure from McCullough's most recent works, Founding Fathers like Benjamin Franklin and Thomas Jefferson, who spent time in Paris, are not covered.  Instead, the book is about 19th-century Americans like James Fenimore Cooper and Samuel Morse, who migrated to Paris and went on to achieve importance in culture or innovation.  Other subjects include Elihu Washburne, the American ambassador to France during the Franco-Prussian War, Elizabeth Blackwell, the first female doctor in the United States, and American artists who worked in Paris such as George Healy, Mary Cassatt, and Augustus Saint-Gaudens.

1776 (book): 1776 (released in the United Kingdom as 1776: America and Britain At War) is a book written by David McCullough, first published by Simon & Schuster on May 24, 2005.  The work is considered a companion piece to McCullough's earlier biography of John Adams, and focuses on the events surrounding the start of the American Revolution.  While revolving mostly around the leadership (and often indecisiveness) of George Washington, there is also considerable attention given to King George III, General Howe, Henry Knox, and Nathanael Greene.  Key Revolutionary War battles detailed in the book include the Battle of Dorchester Heights, the Battle of Long Island, and the Battle of Trenton.  The actual signing of the Declaration of Independence is treated as a somewhat minor detail, as the main focus of the book is on military rather than political events.  The book includes multiple pages of full color illustrations, including portraits and historical battlefield maps made by British engineers at the time.

Shakespeare Wrote for Money: Shakespeare Wrote for Money is a 2008 collection of English author Nick Hornby's "Stuff I've Been Reading" columns for "The Believer".  It contains columns written from August 2006 to September 2008, Hornby's "Stuff I've Been Reading Column."  The introduction is written by American author Sarah Vowell.

An Education: An Education is a 2009 coming-of-age drama film based on a memoir of the same name by British journalist Lynn Barber.  The film was directed by Lone Scherfig from a screenplay by Nick Hornby.  It stars Carey Mulligan as Jenny, a bright schoolgirl, and Peter Sarsgaard as David, the charming con man who seduces her.  The film was nominated for three Academy Awards in 2010: Best Picture and Writing (Adapted Screenplay) for Nick Hornby, and Best Actress for Carey Mulligan.

Kelly McCullough: Kelly David McCullough (born 1967) is a contemporary American author of Fantasy and Science Fiction novels living in Wisconsin.  His critically acclaimed "WebMage" was released in 2006, followed by "Cybermancy" in 2007, "CodeSpell" in 2008, "MythOS" in 2009, and "Spellcrash" in 2010, and other novels since, including the young adult novel "School for Sidekicks".  Some of his 20 published short stories include "The Uncola", "When Jabberwocks Attack", and "The Totally Secret Origin of Foxman: Excerpts from an EPIC Autobiography", a Tor.Com original; he also has written a number of poems, including "The Bees: An Edgar Allan Pooh Poem".  His non-fiction work includes an illustrated collection that is part of a robust middle school physical science curriculum that was funded by the National Science Foundation and has been adopted by several state boards of education, the "Interactions in Physical Science " curriculum.

Juliet, Naked: Juliet, Naked is a novel by the British author Nick Hornby, released on 29 September 2009 by Riverhead Books.  It tells the story of Annie, the long-suffering girlfriend of obsessed music fan Duncan, and the object of his obsession, fictional singer-songwriter Tucker Crowe.  The plot revolves around the release of "Juliet, Naked", the first new Tucker Crowe release in over two decades.  The novel has been compared with Hornby's second novel, "High Fidelity".

Sarahbeth Purcell: Sarahbeth Purcell is an American author of fiction.  Her first book, "Love Is The Drug", was published in 2003 in hardback and in trade paperback in 2004.  Her second book, "This is Not a Love Song" was published in trade paperback in 2005.  Purcell has been compared to Chuck Palahniuk (author of "Fight Club" and "Lullaby", as well as Nick Hornby (well known as the author of "High Fidelity"), and her work has been likened to read more like well crafted songs than words, due in part to her fast paced, deeply observational and lyrical prose.  Purcell is also a visual artist of both photography and paintings.

Supporting paragraphs: David McCullough Nick Hornby
Answer: David Gaub McCullough