His moral philosophy is defined in his college textbook "Elementa Philosophica" as "the Art of pursuing our highest Happiness by the practice of virtue". It was promoted by President Thomas Clap of Yale, Benjamin Franklin and Provost William Smith at The Academy and College of Philadelphia, and taught at King's College (now Columbia University), which Johnson founded in 1754. It was influential in its day: it has been estimated that about half of American college students between 1743 and 1776, and over half of the men who contributed to the "Declaration of Independence" or debated it were connected to Johnson's American Practical Idealism moral philosophy. Three members of the Committee of Five who edited the "Declaration of Independence" were closely connected to Johnson: his educational partner, promoter, friend, and publisher Benjamin Franklin of Pennsylvania, his King's College student Robert R. Livingston of New York, and his son William Samuel Johnson's legal protegee and Yale treasurer Roger Sherman of Connecticut. Johnson's son William Samuel Johnson was the Chairman of the Committee of Style that wrote the U.S. Constitution: edits to a draft version are in his hand in the Library of Congress.