1921
| Jan 25 | Resigns from Naval Consulting Board following a prolonged debate over the location and mission of the proposed naval research laboratory. |
| July | Takes a camping trip in Maryland with Harvey Firestone and President Warren G. Harding. |
1922
| May | Outlines a plan for reforming the monetary system by extending credit to farmers based on the cash value of their crops. |
| June | Is awarded an honorary Doctor of Science degree by Rutgers University. |
1923
| Aug 1 | Along with Henry Ford and Harvey Firestone, attends the funeral of President Warren G. Harding in Marion, Ohio. With his wife Mina, vacations in Canada and visits with the Ford family in Detroit until the end of the month. |
1924
| Aug 28 | Consolidates the Edison Phonograph Works into Thomas A. Edison, Inc. |
1926
| Feb 1 | Sells all of his domestic and foreign patents to Thomas A. Edison, Inc. for $78,200.59 in cash. |
| Aug 2 | Steps down as president of Thomas A. Edison, Inc., in favor of his son Charles; becomes chairman of the board. |
| Oct 26 | Introduces long-playing disc records in an effort to salvage his declining phonograph business. Also begins offering attachments so that his phonographs can play the laterally-cut records of his competitors. |
1927
| July | Organizes the Edison Botanic Research Corporation to develop a process for producing rubber from plant substances native to the United States. |
1928
| Apr | Reluctantly agrees to Charles Edison's suggestion that the company enter the radio business. Takes control of the Splitdorf-Bethlehem Electrical Co. of Newark. |
| Oct 20 | Receives a special Congressional Medal for "illuminating the path of progress through the development and application of inventions that have revolutionized civilization in the last century." The award is presented by U.S. Secretary of the Treasury Andrew W. Mellon at a ceremony broadcast to thirty million radio listeners. |
1929
| Feb 11 | Celebrates his eighty-second birthday at Fort Myers with President-elect Herbert Hoover, Henry Ford, and Harvey Firestone. |
| July 28 | Forty-nine finalists participate in the competition for the first Edison Scholarship Contest. Wilber B. Huston, the son of the Episcopalian Bishop of Seattle, is named the winner. |
| Oct 21 | Attends the opening and dedication of Greenfield Village and the Henry Ford Museum, intended to coincide with the Golden Jubilee (fiftieth anniversary) of the invention of the incandescent light. President Herbert Hoover and more than five hundred invited dignitaries also attend. |
| Oct 28 | Stops production of phonograph records; shifts production emphasis from phonographs to radios. |
1931
| Jan 6 | Executes his last patent application. |
| Oct 18 | Dies at Glenmont. |
