Morehead graduated from University of North Carolina-Chapel Hill in 1891 and was a member of Sigma Alpha Epsilon fraternity.
He was a noted philanthropist who made major gifts to his alma mater, the University of North Carolina at Chapel Hill. He also served as mayor of Rye, New York and United States Ambassador to Sweden. One of his notable early scientific discoveries was the development of an economical process for the manufacture of calcium carbide.
He was also an authority on the analysis of gases, having invented a device for the purpose and written a book on the subject.
Morehead married Genevieve Margaret Birkhoff. He had no children. He devoted his considerable fortune to philanthropy, especially to the benefit of University of North Carolina-Chapel Hill.
He also gave the University the Morehead Planetarium, later renamed the Morehead Planetarium and Science Center. One of Morehead"s particular interests was in providing financial assistance to students attending University of North Carolina-Chapel Hill.
To that end he endowed the John Motley Morehead Foundation, which each year awards generous scholarships (for undergraduate work) and fellowships (for the graduate and professional schools) to applicants chosen through an extensive and competitive screening process.
The Morehead-Cain Scholarship is the oldest merit-based scholarship in the United States. Morehead served as minister to Sweden from 1930 to 1933. He was awarded the North Carolina Award,the highest civilian award bestowed by the United States. state of North Carolina in the category of Public Service in 1964.
Descendants include Jean Motley Morehead Larkin, John L. Morehead, West. Harris Nelson, William Her Majesty Nelson III.
There is a section of Interstate 40 named after him, called the John Motley Morehead III Freeway, that passes through Chapel Hill, North Carolina and most of the eastern end of Orange County.