Early records of grades received by students did include an E. One record from Holyoke College indicates an E being used, but it was the lowest grade, as an F is now. Some time later the administrators changed the failing grade to an F, still retaining the E as standing for grades between 75 to 79 percentile. No specific date is discernable as to when E was eliminated but most colleges had discontinued its use by 1930. It was speculated that the instructors during this time were concerned that the E grade would be mistaken for “excellent”.
There is some thought that the letter E was eliminated from all but primary schools to avoid confusion as the primary schools used the letters E, S, N, and U to signify Excellent, Satisfactory, Needs improvement, and Unsatisfactory. Some used E to stand for effort and good behavior, rather than F standing for failure of a well-behaved child.
There is some speculation that E was eliminated as a grade because an F could be easily changed to an E. A child could tell father his grade was E and it stood for excellence, and if the father was in the habit of paying for good grades, the father could be scammed.