Margaret "Peggy" Olson is a fictional character in the AMC television series "Mad Men", and is portrayed by actress Elisabeth Moss.
 Initially, Peggy is secretary to Don Draper (Jon Hamm), creative director of the advertising agency Sterling Cooper.
 Later, she is promoted to copywriter, the first female writer at the firm since World War II.
 She later joins Draper when he leaves Sterling Cooper to become a founding member of Sterling Cooper Draper Pryce.
 By the end of Season 4, Peggy is effectively Draper's second-in-command in the creative department.
 Towards the end of season five, Peggy accepts a job offer from another agency, CGC, and quits her job at Sterling Cooper Draper Pryce.
 However, following a merger between SCDP and CGC, Peggy finds herself working again with Don Draper.
Donald Francis "Don" Draper is a fictional character and the protagonist of AMC's television series "Mad Men", portrayed by Jon Hamm.
 Up to the Season 3 finale, Draper was creative director of Manhattan advertising firm Sterling Cooper.
 He then became a founding partner at a new firm, Sterling Cooper Draper Pryce, after he and his superiors left their previous agency in advance of an unwanted acquisition.
 The agency later merged with a rival firm, Cutler Gleason & Chaough, to become Sterling Cooper & Partners while pursuing a contract from Chevrolet.
Jonathan Daniel Hamm (born March 10, 1971) is an American actor, director, and television producer best known for playing advertising executive Don Draper for the AMC television drama series, "Mad Men" (2007–2015).
Jared Scott Gilmore (born May 30, 2000) is an American teen actor.
 He is best known for his roles in "Mad Men" as Bobby Draper and for the series "Once Upon a Time" as Henry Mills.
 He won the Young Artist Award for Best Performance in a TV Series – Leading Young Actor in 2012 for his role in the latter series.
"Generalissimo" is the tenth episode of the third season of the American television comedy series "30 Rock".
 It was written by executive producer Robert Carlock and directed by Todd Holland.
 The episode originally aired on the National Broadcasting Company (NBC) in the United States on February 5, 2009.
 Guest stars in "Generalissimo" include Jon Hamm, Salma Hayek, Patrick Heusinger, Matt Lauer, Doug Mand, Greg Tuculescu, and Teresa Yenque.
Roger H. Sterling Jr., played by John Slattery, is a fictional character on the AMC TV series "Mad Men".
 He formerly worked for Sterling Cooper, an advertising agency his father co-founded in 1923, before he became a founding partner at the new firm of Sterling Cooper Draper Pryce in late 1963.
"Public Relations" is the season premiere of the fourth season of the American television drama series "Mad Men", and the 40th overall episode of the series.
 It was written by series creator and executive producer Matthew Weiner, and directed by Phil Abraham.
 It originally aired on AMC in the United States on July 25, 2010.
 The episode takes place in November 1964, as the advertisement agency Sterling Cooper Draper Pryce has just started up, and Don Draper (Jon Hamm) is struggling with his divorce.
 The agency partners are concerned about the narrow breadth of their client base, which is not helped by Don coming across as less than sympathetic in an interview with a trade magazine.
 Peggy Olson (Elisabeth Moss) attempts a viral marketing stunt to bring back a disgruntled client, with unexpected repercussions.
 Meanwhile, Don's ex-wife Betty (January Jones) is struggling to fit in with her new family, and Don encounters problems in his romantic life.
Phil Abraham is an American cinematographer and television director.
 He worked on all six seasons of "The Sopranos", initially as a camera operator, then as a cinematographer and eventually as an episodic director.
 He won the 2008 Primetime Emmy Award for Outstanding Cinematography for a One Hour Series for his work on the pilot of "Mad Men" and has been nominated for four other Primetime Emmy Awards for Outstanding Cinematography for a Single-Camera Series for his work on "The Sopranos".
 Besides working as a cinematographer for "Mad Men", he has also worked as a director for fifteen episodes.
 He picked up two more nominations for a Primetime Emmy Award for Outstanding Directing for a Drama Series for "Mad Men" episodes "The Jet Set" and "The Other Woman".
 He attended high school at York Preparatory School and graduated from Wesleyan University, along with "Mad Men" creator Matthew Weiner.
John M. Slattery Jr. (born August 13, 1962) is an American actor and director.
 He is best known for his role as Roger Sterling in the AMC drama series "Mad Men" and for his role as Howard Stark in cameo appearances in the Marvel Cinematic Universe films "Iron Man 2", "Ant-Man", and "".
 He has received four Primetime Emmy Awards nominations and two Critics' Choice Television Awards for "Mad Men".
 He was also part of the "Mad Men" ensemble cast that won two SAG Awards.
"The Good News" is the third episode of the fourth season of the American television drama series "Mad Men", and the 42nd overall episode of the series.
 It was written by Jonathan Abrahams and series creator and executive producer Matthew Weiner, and directed by Jennifer Getzinger.
 It aired originally on the AMC channel in the United States on August 8, 2010.
 The episode contained guest appearances by, among others, Melinda Page Hamilton as Anna Draper and Samuel Page as Greg Harris.

Question: What TV series included Don Draper from Mad Men as a guest star in its third season?
Answer: 30 Rock