1829: The Elementary Spelling Book, being an Improvement on the American Spelling Book. Webster took back control of his Speller by revising & re-naming it as a new, independent work, not under the control of Hudson. This edition was also popularly called the “Blue-backed speller,” and it became another great success, due largely to Webster’s personal popularity and his again being very personally involved in the book's promotion and copyright protection. This edition of his Speller was the first to fully replace the numerical system of pronunciations of vowels with diacritical marks similar to those used in dictionaries today. (Note: Benjamin Franklin and George Washington were close personal friends of Webster, and by 1829 at age 70, he was highly respected and admired by most members of Congress who had grown up using his Spellers. Webster was also one of our founding fathers who, along with Franklin, Washington, Paine and Jefferson, had long used his newspapers and books to advocate and promote the adoption of our constitutional federal form of government. Noah Webster died on May 28, 1843, while working on an update to his Dictionary.) 1857: Noah’s son, William Webster, revised & republished his father’s Elementary Spelling Book, partly in order to make its pronunciation key conform to the 1828 dictionary. This edition likewise was many times reprinted through the late 1800s (sold to many freed former slaves), and at least as late as a 1908 printing. However, William also began to alter some of his father’s work: e.g. saying it was mostly for pronunciation & spelling, not for also first learning to read; and stating that understanding the meanings of words practiced was not important at first, not until later when a child’s ability to understand grew; and saying the pronunciation of th in thin and in this are the same - except one is articulated with breath and the other with vocal sound - which is not quite accurate; etc., not the best edition. 1857: The G. & C. Merriam company of Philadelphia bought full rights to Webster’s American Dictionary but not his Speller. However, Merriam was one of several licensed publishers of the Speller, and so published son William’s 1857 revision then (and again an 1880 edition), while the Webster family retained the principal copyright and ownership. I’m not sure but it appears 1857 was the last major revision/edition of the Speller. 1857-1908: As near as I've been able to find, it appears that Webster’s family retained principal ownership (full copyrights) to the Speller after 1857, but Noah and his family had licensed several different publishing companies rights to publish his Spellers. Four such companies (Ivison, Appleton, Barnes & Van Antwerp, and Harper) sold their rights to a 5th, the American Book Company, which apparently thereby gained sole or nearly sole rights to publish it, circa 1890, but not full ownership copyrights. If then-current copyright law had a 50-year limit, the last 1857 revised edition expired in 1907. The last new publication I've been able to find is a 1908 edition or reprint, which shows The American Book Company still held the publishing copyright. Even granting that one major competing work on the subject (McGuffey’s Speller) had gained a large share of the market by 1908, it was nevertheless a mystery why there were no further printings of Webster’s.