約翰·英格拉姆·麥克莫蘭出生於美國密西根州古德蘭鎮區，為喬治·麥克莫蘭（George McMorran，1859年10月15日－？）和利迪亞·英格拉姆（Lydia Ingram）所生育當中最年長的子女。前美國眾議員亨利·戈登·麥克莫蘭（1844年－1929年）也是英格拉姆·麥克莫蘭的表親。他的親妹妹莉莉亞·伊麗莎白·韋布（Lillia Elizabeth Webb，婚前名為莉莉亞·伊麗莎白·麥克莫蘭）在世103歲。麥克莫蘭有吸煙、飲酒以及吃油膩食物等習慣。
- Oliver, Myrna. J. McMorran, 113; Oldest Man in U.S., 5th-Oldest Ever.. 洛杉磯時報. February 27, 2003 [2007-12-18].
McMorran was history's fifth-oldest man, said Dr. L. Stephen Coles of the 加州大学洛杉矶分校-based Gerontology Research Group, a nonprofit international research organization that verifies birth dates and tracks the 35 to 45 people around the globe who are 110 and older. Coles said that 41 people remain alive in that category, and that the oldest living American is Mary Christian – one week McMorran's senior – of San Pablo, Calif. The verifiably oldest living man in the United States, he said, is now Fred Hale of New York state, who is 112.
- America's Oldest Man Parties On.. 美联社 in Miami Herald. 2002-06-21 [2007-12-18].
So what does a man believed to be the oldest American do on his birthday? He has a party, of course. After 113 birthdays, they've become routine for John Ingram McMorran. For his relatives, the event was more emotional. Tears rolled down great-grandson's Scott McMorran's cheeks at Wednesday's party. 'It's not the long life [that's so important]. It's the person, not the age,' ...
- Social Security Death Index at ancestry.com
- Briefly nation's oldest, Mary L. Parr dies at 113.. St. Petersburg Times. [2007-12-18].
McMorran, a retired farmer and truck driver who smoked a pack of cigarettes a day at one point, became the heir apparent until 老人學, a 洛杉矶 investigator for the Gerontology Research Group, found Miss Parr.
- The immortals Farewell to some of the world's more off-beat legends.. 獨立報. December 28, 2003.
John McMorran America's oldest man, who departed this world at the age of 113, despite spending more than a century smoking, drinking and eating greasy food ...
- Associated Press staff. Oldest American man, 113, dies in Florida. World News (雪梨晨鋒報). February 26, 2003 [2007-12-09].
- Dr. L. Stephen Coles (interviewer). World's Second-Oldest Living Man, Mr. John McMorran. Gerontology Research Group. 2000-08-06 [2007-12-17].
- Mike Connell. Michigan Man May Be the Oldest Living Man. Gerontology Research Group page on Mr. McMorran (Port Huron, Michigan: Times Herald News). 2000-08-06 [2007-12-17].