Masterworks of Literature

These titles were evidently softcover reprints of titles from Twayne's hardcover U.S. Classics series. This information is gleaned from the fact that three of these titles show up in PW annotations in hardcover as being published by Twayne. There's no mention of the softcover series in PW at all, but information is available elsewhere. College and University Press had an arrangement with Twayne to republish their hardcover United States Authors Series in softcover editions, so it's not surprising that they would also publish this series.

The series continued for a number of years without M- series numbers.