among the best stories I first encountered in K-12 textbooks:

My 6th grade Scott, Foresman reading text


It saddens me to report that not a one of these below was actually assigned or read, as far as I know, by anyone in the classes but me, even when the text was in use in a classroom...though, for example, Ray Bradbury's "All Summer in a Day" was so employed, from the 7th grade text referred to below. More guidelines for our teacher to use the Bradbury, I suspect. And, of course, she recognized that name.

"Desertion" by Clifford Simak...a Scott, Foresman 7th-grade reading text

"Brightside Crossing" by Alan Nourse...the same text

The Door in the Wall, a novella by Marguerite de Angeli, which won the 1950 Newbery Award, found in a paperback text anthology on sale at a W.T. Grant's for 33.3c ca. 1974

"The Summer of the Beautiful White Horse" by William Saroyan (the first chapter of My Name is Aram), which I first read in a slightly battered copy of a junior-high-school reading text when I was about ten or so.

A basketball novel by William Campbell Gault (probably not Showboat in the Back Court, but an earlier one), which was the final work in a eighth-grade text for slow readers (part of the Scott, Foresman Open Highways series, if I remember correctly) that I read when I was in fifth grade (having read a few of Gault's sports-pulp short stories in various auto-racing and other sports-fiction anthologies)

"The Joker's Greatest Triumph" by Donald Barthelme, in an American literature text from 11th grade...almost certainly also a Scott, Foresman...(we did read, in class, Arthur Miller's All My Sons from that text...)

"Los dos reyes y los dos laberintos" by Jorge Luis Borges, in Imaginacion y fantasia edited by Donald Yates and John Dalbor, a literature text for Anglophone Spanish language students I picked up as a remainder somewhere ca. 1979 (certainly not the first Borges I read, but the first Borges in the original...was even able to read it to my AP Spanish class with apparently reasonably good comprehension on my fellow-students' part)

and, cheating a bit by citing classroom-use magazines rather than texts:
"Test" by Ted Thomas, reprinted in an issue of Read, the Xerox Educational Services magazine, ca. 1976

"The Battle of Chickamauga" by Ambrose Bierce, reprinted in either Scholastic Scope or Literary Cavalcade, the Scholastic Magazines publications, ca. 1976

Read through its ages...

in 1962

in 1971, looking much as I remember it

in 2011

The 1950s textbooks I would occasionally collect, such as Adventure Bound (below left)  often seemed rather exotic. Certainly exuberant and expensively-produced. Earlier similar items often seemed very drab in comparison.