Born into a powerful southern family, McClung was raised in Memphis, Tennessee until he was accepted into Lehigh University.

Immediately establishing himself as a skilled sportsman, McClung participated on both the school's football and baseball teams.

He was also named starting quarterback of the school's football team and led the squad to a 6-4 record, which included two wins over rival Lafayette.

In 1895, McClung was hired by the United States Naval Academy to replace William Wurtenburg as the head coach of their football program.

He took over during a period at the Academy when, according to historian Morris Allison Bealle, "football was waning in Annapolis" and that "there was no climax incentive to steam up players".

[15] His team played at home for the entire season, due to restrictions put forth by president Grover Cleveland following the bloody 1893 Army-Navy Game.

[15] Virginia was the next team on Navy's schedule, but their opponents were forced to forfeit the match after a fire destroyed one of the campus's major structures.

[20] Because of McClung's scheduling, the Naval Academy in 1896 banned the football team from playing another athletic club.

He began as early as November 1895, when he partnered with Paul Dashiell to officiate a game between Yale and Princeton.

Former Princeton guard William "Big Bill" Edwards stated that "within my recollection, for many years the two most prominent, as well as most efficient officials, whose names were always coupled, were McClung, Referee, and Dashiell, Umpire.

After the Yale-Princeton game, a writer for the New York Tribune stated that Dashiell and McClung were "excellent" at their jobs and "that their rulings were just and impartial was admitted everywhere".

[25] He was a top candidate for umpiring a contest between Wisconsin and Carlisle in what would be one of the first games played at night, but did not receive the position.

The contest, which ended in a 0-0 tie, was the first time the rivalry was played since a bloody 1894 game led it to be cancelled.

[45] As with the previous year, McClung was selected prior to the 1904 season's beginning as the referee for three games for Yale, against Columbia, Princeton, and Harvard.

The first game of the season was between Harvard and Pennsylvania, which McClung officiated alongside "Big Bill" Edwards.

Edwards eventually accepted the umpire role, and remained at the position for the rest of his officiating career following the game.

[51] The officials' decision remained a big problem for college football for some time, and eventually then-president Theodore Roosevelt met with Dashiell to discuss the play.

[51][52] Following the season's conclusion, McClung joined other prominent football personnel in selecting that year's All-America team.

McClung's selection included seven players who were later recognized as consensus All-Americans, and one of which, Tom Shevlin, would later make the Hall of Fame.

[57][58] While working at the Joliet Blast Furnaces, McClung developed a severe tooth infection, which eventually gave him blood poisoning.

He wrote that: "Richard Harding Davis and [McClung] were two Lehigh men whose position in the football world was most prominent.