"Marcie is one-up on Peppermint Patty in every way. She sees the truth of things, where it invariably escapes Patty. I like Marcie."
Charles M. Schulz on Marcie
Marcie, forever known for her unassuming sweetness and intellect, was officially introduced into the cast of Charles M. Schulz's Peanuts comic strip on July 20, 1971 (although a look-alike character named "Clara" appeared in the strip with her friend Sophie as early as 1968). In the TV special, You're in the Super Bowl, Charlie Brown, Marcie is given the last name Johnson, although this was never used in the strip, so can not be canon. As for her family, in one strip Marcie states that her mother is designing a freeway, indicating that her mother is a civil engineer.
Marcie was first introduced as a camp attendee with Peppermint Patty in 1971. However, she is not given a name until later that year, on October 11th. The friendship between Marcie and Peppermint Patty started off unassumingly; with Marcie calling Peppermint Patty "Sir" in the very beginning, and Peppermint Patty calling Marcie a "dorky kid" in response. Over time, Marcie's character developed more fully, though she fits best as a supporting player and Peppermint Patty's best friend.
Marcie is an intellectual and a bookworm. She is well known for the high quality of her schoolwork, which provides a perfect contrast to Peppermint Patty's ineptness and has provided dozens of punchlines in the strip. She also has a talent for ice skating and music, she has taken organ lessons with Mrs. Hagemeyer (Miss Othmar's married name). Although not a hater of athletics (she admired the success of Billie Jean King, for example, and also likes caddying golf), her knowledge of sports often seems to be lacking and the rules appear to confuse her (Peppermint Patty: "There's no penalty box in baseball!").
Marcie also has a deep appreciation for the arts. In addition to her organ playing, many of the series' later gags involve her attending "Tiny Tots" concerts with Peppermint Patty, where she once again plays "straight man" to Peppermint Patty's cluelessness about the concerts themselves.
When the actions of Snoopy's World War I flying ace alter-ego shifted from fighting the Red Baron to fighting the demons of lost love and loneliness, Marcie would act as friend, confidant, and ultimately the "French Lass" for the flying ace on his sojourns to the Moulin Rouge.
Despite catering to Snoopy's fantasy thoughts, it is Marcie herself who finally shouts out to Peppermint Patty (after a suspenseful fight sequence) that Snoopy's doghouse is not a guest cottage and that Snoopy himself is a beagle, not "that funny looking kid with the big nose."
Such outbursts by Marcie, however, are very rare; and do not disguise the fact that she is one of the all-around sweetest, most caring, and smartest of the characters in Peanuts.
See main article: Peppermint Patty and Marcie's relationship
Marcie is considered Peppermint Patty's sidekick and she likes hanging out with her. Although Patty can at times get on her nerves; it bugs Marcie how poorly Peppermint Patty does in school, and how she will never do her work. It also bugs her that Peppermint Patty will never tell anyone about her love for Charlie Brown. However, Marcie looks up to Peppermint Patty, and thinks she is a great friend.
See main article: Marcie and Charlie Brown's relationship
Marcie has affectionate feelings for Charlie Brown as well. Unlike Peppermint Patty, Marcie is not the kind to hide her emotions, often speaking openly and from the heart. She is always rebuffed, however, as Charlie Brown never quite gets the message.
Marcie has played with Snoopy in his fantasy life. On some occasions, Snoopy has been shown to have a love interest in Marcie, but Marcie never returns his feelings.
- Marcie is one of the many Peanut characters to appear in the game Snoopy's Street Fair, in which, she owns a book stall.