“An accusation of being patronizing would be a small price to pay for the positive results that would accrue!” he wrote. Mr. Kelly suggested that Mr. Schulz begin with a “supernumerary” black character, a de facto extra, who “would quietly and unobtrusively set the stage for a principal character at a later date.” This cautious approach would serve the dual purpose of not burdening Mr. Schulz and “Peanuts” with the duty of making a Major Social Statement and presenting friendship between black and white children as utterly normal.

But in the context of the late ’60s, Franklin’s debut was indeed a Major Social Statement. Inevitably, a few newspaper editors in the South made noises of protest, but by and large, the reaction to Franklin was positive, particularly among black readers.

Morrie Turner, whose “Wee Pals,” introduced in 1965, was the first widely syndicated strip by an African-American cartoonist, told Mr. Schulz in a letter that he found the “handling and the treatment of the character excellent,” adding, “The day Little Orphan Annie has a black boyfriend, we’ll really have it made.” More earnestly, a young black Army sergeant in Vietnam, Franklin R. Freeman, wrote to Mr. Schulz to express how gratifying it was to find “a new character in the strip who shares my name.”

For Barbara Brandon-Croft, who in 1991 became the first African-American woman to have a nationally syndicated comic strip in the mainstream press, “Where I’m Coming From,” the simple fact of Franklin’s addition to the mix was downright exhilarating. Ms. Brandon-Croft was 10 years old in 1968, and she told me: “I remember feeling affirmed by seeing Franklin in ‘Peanuts.’ ‘There’s a little black kid! Thank goodness! We do matter.’”

In the long run, Franklin ended up existing in a space somewhere between supernumerary and principal, most reliably serving as the academically proficient straight man to Peppermint Patty’s perpetually D-minus-pulling goofball. Like a lot of “Peanuts” fans, I wish Franklin had been given greater depth and more to do. In that very first series of strips, he mentioned that his father, like Sergeant Freeman, was away in Vietnam. Franklin and Peppermint Patty (and Marcie) attended a school on the other side of town from the strip’s core characters.