Answer:
Senator Warren G. Harding
Step-by-step explanation:
Fact #7: The phrase "Founding Fathers" was popularized by Warren G. Harding. Now a commonly used phrase, the term did not appear widely until after the 29th President of the United States, Warren G. Harding, began using it in many of his speeches in the late 1910s and early 1920s. (according to battlefields.org)