You can get an A, B, C, D, or F in a class—whatever happened to E? It was used at one point, writes Brian Palmer in Slate’s Explainer column. At Mount Holyoke College, which boasts the earliest record of letter grades, it was given for scores of 74 or below and represented failure. One year later, in 1898, the scale was tweaked and F was added for failing grades, while E was still used for scores slightly above F range.
Sometime between that and 1930, though, E had disappeared from most colleges. Some professors were concerned it would be mistaken for “excellent,” even though, Palmer writes, “there's no evidence of similar concerns over, say, B—which might just as well stand for ‘brilliant’ as ‘bungled.’” Grades in general are somewhat modern, he adds, a result of increased school attendance. Before letter grades, some colleges separated students into groups of “best,” “worse,” and “worst,” or similar.
(More grades stories.)