Question: Which Harrison Ford film was directed by George Lucas before his success with Star Wars; American Graffiti, Dynasty, or The Conversation?

Context paragraphs:
Han Solo: Han Solo is a character in the "Star Wars" franchise.  In the original film trilogy, Han and his co-pilot, Chewbacca, became involved in the Rebel Alliance's struggle against the Galactic Empire.  During the course of the "Star Wars" narrative, he becomes a chief figure in the Alliance and succeeding galactic governments.  "Star Wars" creator George Lucas described the character as "a loner who realizes the importance of being part of a group and helping for the common good".  Harrison Ford portrayed the character in the original "Star Wars" trilogy as well as "".  Alden Ehrenreich will portray a young Han Solo in an upcoming, as yet untitled spinoff film.

Slipstream (1989 film): Slipstream is a 1989 science fiction film directed by Steven Lisberger, who had previously directed the cult classic 1982 science fiction film "Tron".  It was produced by Gary Kurtz, best known for his collaboration with George Lucas on the first two "Star Wars" films and "American Graffiti".  "Slipstream" reunited Kurtz with his "Star Wars" lead Mark Hamill, who features alongside Bill Paxton, Bob Peck and Kitty Aldridge, with cameo appearances from Robbie Coltrane, Ben Kingsley and F. Murray Abraham.

Star Wars (film): Star Wars (later retitled Star Wars: Episode IV – A New Hope) is a 1977 American epic space opera film written and directed by George Lucas.  It is the first film in the original "Star Wars" trilogy, the first "Star Wars" movie in general, and the beginning of the "Star Wars" franchise.  Starring Mark Hamill, Harrison Ford, Carrie Fisher, Peter Cushing, Alec Guinness, David Prowse, James Earl Jones, Anthony Daniels, Kenny Baker, and Peter Mayhew, the film's plot focuses on the Rebel Alliance, led by Princess Leia (Fisher), and its attempt to destroy the Galactic Empire's space station, the Death Star.  This conflict disrupts the isolated life of farmhand Luke Skywalker (Hamill), who inadvertently acquires a pair of droids that possess stolen architectural plans for the Death Star.  When the Empire begins a destructive search for the missing droids, Skywalker accompanies Jedi Master Obi-Wan Kenobi (Guinness) on a mission to return the plans to the Rebel Alliance and rescue Leia from her imprisonment by the Empire.

The Empire Strikes Back: The Empire Strikes Back (also known as Star Wars: Episode V – The Empire Strikes Back) is a 1980 American epic space opera film directed by Irvin Kershner.  Leigh Brackett and Lawrence Kasdan wrote the screenplay, with George Lucas writing the film's story and serving as executive producer.  The second installment in the original "Star Wars" trilogy, it was produced by Gary Kurtz for Lucasfilm and stars Mark Hamill, Harrison Ford, Carrie Fisher, Billy Dee Williams, Anthony Daniels, David Prowse, Kenny Baker, Peter Mayhew, and Frank Oz.

Star Wars: The Force Awakens: Star Wars: The Force Awakens (also known as Star Wars: Episode VII – The Force Awakens) is a 2015 American epic space opera film co-written, co-produced and directed by J. J. Abrams.  The sequel to 1983's "Return of the Jedi", "The Force Awakens" is the first installment of the "Star Wars" sequel trilogy.  It stars Harrison Ford, Mark Hamill, Carrie Fisher, Adam Driver, Daisy Ridley, John Boyega, Oscar Isaac, Lupita Nyong'o, Andy Serkis, Domhnall Gleeson, Anthony Daniels, Peter Mayhew, and Max von Sydow.  Produced by Lucasfilm Ltd. and Abrams' production company Bad Robot Productions and distributed worldwide by Walt Disney Studios Motion Pictures, "The Force Awakens" was the first "Star Wars" film not produced by franchise creator George Lucas.  Set 30 years after "Return of the Jedi", it follows Rey, Finn and Poe Dameron's search for Luke Skywalker and their fight alongside the Resistance, led by veterans of the Rebel Alliance, against Kylo Ren and the First Order, a successor to the Galactic Empire.

American Graffiti: American Graffiti is a 1973 American coming-of-age comedy-drama film directed and co-written by George Lucas starring Richard Dreyfuss, Ron Howard, Paul Le Mat, Harrison Ford, Charles Martin Smith, Cindy Williams, Candy Clark, Mackenzie Phillips, Bo Hopkins, and Wolfman Jack.  Suzanne Somers and Joe Spano also appear in the film.  Set in Modesto, California in 1962, the film is a study of the cruising and rock and roll cultures popular among the post–World War II baby boom generation.  The film is told in a series of vignettes, telling the story of a group of teenagers and their adventures over a single night.

Han shot first: "Han shot first" is a phrase referring to a controversial change made to a scene in the science fiction film "Star Wars" (1977), in which Han Solo (Harrison Ford) is confronted by the bounty hunter Greedo (Paul Blake) in the Mos Eisley cantina.  The change was made for the 1997 Special Edition re-release of "Star Wars", and has since been altered twice more.  The phrase "Han shot first" is meant to express that "Han was the only one who shot", and is a colloquial retort to series creator George Lucas's decision to alter the scene.

Star Wars: The Clone Wars (2008 TV series): Star Wars: The Clone Wars is an American 3D CGI animated television series created by George Lucas and produced by Lucasfilm Animation with the division Lucasfilm Animation Singapore, Lucasfilm and CGCG Inc.  The series debuted on the US version of Cartoon Network on October 3, 2008.  It is set in the fictional "Star Wars" galaxy during the three years between the prequel films "" and "", the same time period as the previous 2D 2003 TV series "".  Each episode has a running time of 22 minutes to fill a half-hour time slot.  In 2007, "Star Wars" creator George Lucas stated "there will be at least 100 episodes produced [about five seasons]".  Dave Filoni is the supervising director of the series.  Genndy Tartakovsky, director of the first "Clone Wars" series, was not involved with the production, but character designer Kilian Plunkett referred to the character designs from the 2D series when designing the characters for the 3D series.  There is also an online comic, depicting story-snippets between the single episodes.

Return of the Jedi: Return of the Jedi (also known as Star Wars: Episode VI – Return of the Jedi) is a 1983 American epic space opera film directed by Richard Marquand.  The screenplay by Lawrence Kasdan and George Lucas was from a story by Lucas, who was also the executive producer.  It was the third installment in the original "Star Wars" trilogy and the first film to use THX technology.  The film is set one year after "The Empire Strikes Back" and was produced by Howard Kazanjian for Lucasfilm Ltd.  The film stars Mark Hamill, Harrison Ford, Carrie Fisher, Billy Dee Williams, Anthony Daniels, David Prowse, Kenny Baker, Peter Mayhew and Frank Oz.

Dynasty (film): Dynasty is a 1976 NBC television film directed by Lee Philips.  It stars Harrison Ford, Sarah Miles and Stacy Keach.  The film was made during the period before "Star Wars" in which Ford's career was gaining momentum after his roles in "American Graffiti" and "The Conversation".

Supporting paragraphs: Dynasty (film) American Graffiti
Answer: American Graffiti