Franklin is a character in the Peanuts
He first appeared in a syndicated strip on July 31, 1969. Franklin bumps into Charlie Brown at a beach after retrieving his ball, and Chuck discovers that Franklin attends the same school as Peppermint Patty and Marcie. Shortly after Franklin travels over to Charlie Brown's neighborhood looking for Charlie Brown and his gang, but was spooked by the idiosyncrancies of Snoopy, Lucy and Linus. Franklin then periodically appeared playing baseball as a centre-fielder, and engaging in deep conversations with Charlie Brown (they liked to talk about their grandparents) or Linus Van Pelt (the both quoted the Old Testament to each other).
Of note is that Franklin was the first African-American character to appear in a mainstream comic strip in a non-subordinate role (unlike Mandrake's manservant Lothar). Franklin appeared at about the same time as several American cities were going up in smoke during the 1969 summer of race riots. Charles Schultz made scant reference to Franklin's ethnicity in the series, except to perhaps sanguinely imply that children are colour-blind and free of prejudice. Perhaps the only controversial issue concerning Franklin was that his father was serving in Vietnam.
There was at first only some minor criticism of Franklin appearing in a desegregated classroom with Peppermint Patty. Later other critics would note that Franklin, while devoid of any sterotypical African-American traits, seemed to lack any personality or ideosyncracies that would make him stand out and be anything other than a foil for the other messed up members of the Peanuts gang. Rarely does he say anything foolish or funny, and so unlike the egotistical Lucy or obsessive Schroeder he is not a particuarly interesting. The first mainstream African-American characters, like Chuck in the Archie comics or Gordy Howard in The Mary Tyler Moore Show, were also panned for being irrelevant, tokenistic characters. On stylistic matters, I find that Franklin's dark complexion is crudely illustrated by dense cross-shading when he appears in black and white strips.
In the animated special You're in the Super Bowl, Charlie Brown, Franklin's surname is revealed to be Armstrong.