About a century ago, a young baseball player from Abilene, Kan., struggled with the distinction between professional and amateur sports. This was Dwight D. Eisenhower, the future World War II Allied supreme commander in Europe and two-term president of the United States.

Ike’s predicament has a distant contemporary echo in this year’s ruling by a regional director of the United States National Labor Relations Board that college students on athletic scholarships should be deemed school employees, which would enable them to join labor unions. This ruling, now being contested, has reignited a decades-long controversy over how exactly to define college and university athletes.

Growing up in a relatively poor family, born in 1890, the third of six brothers, Eisenhower, as a small boy, declared his ambition “to be a real major league ballplayer, a real professional like Honus Wagner.” In the early 20th century, Wagner was at the apogee of his career playing shortstop for the Pittsburgh Pirates; Ty Cobb called Wagner “maybe the greatest star ever to take the diamond.” (With uncharacteristic gushing, President Eisenhower wrote Wagner in 1954 on his 80th birthday, “You are truly one of baseball’s immortal heroes.”)

At Abilene High School, an almost swaggering Ike played center field while his brother Edgar, one year older, played first base. After graduation in 1909, Dwight worked in the town’s Belle Springs Creamery to finance Edgar’s education at the University of Michigan; Edgar had pledged to drop out later and do the same for him.

Instead Dwight sought and won a merit appointment to the United States Military Academy. There he failed to make the varsity baseball team, which he called “one of the greatest disappointments of my life.”

He played West Point varsity football but badly damaged his knee. Told he could never again play team sports, he was plunged into despair. “Life seemed to have little meaning,” he later recalled. “A need to excel was gone.”

What seemed like a personal disaster to the young Eisenhower, however, may have been, in retrospect, good luck. During his interregnum after high school, he indulged what might at least be described as some corner-cutting that could conceivably, under the most draconian scenario, have gotten him disqualified from West Point, making his later glorious military and political career unlikely. And continuing to play on a varsity team would have increased his risk of exposure and punishment.

Before entering West Point, by his own sporadic testimony, Ike evidently played baseball for money, disguising himself behind the pseudonym “Wilson” to avoid jeopardizing his amateur standing, which was essential to play college football and baseball. Such an expedient was not unknown in those times, but it would have opened the young Eisenhower to the charge that, at least technically, he had deceived West Point, with its vaunted honor code, by attesting that he had never played sports for money.

Seemingly unaware that some people might view such legerdemain as a lapse in his world-renowned personal character, Eisenhower later reminisced about the episode as if it were a youthful picaresque caprice.

The New York Times of June 20, 1945, reported on a conversation he had before joining Mayor Fiorello La Guardia to watch the Giants play the Boston Braves at the Polo Grounds. That morning, six weeks after V-E Day, the supreme commander, in five-star uniform, had been mobbed in what The Times called “the largest and most enthusiastic” parade in New York’s history — “a triumph such as Rome never gave a conquering Caesar.”

The Giants’ manager, Mel Ott, asked Gen. Eisenhower whether it was true that he had played semiprofessional ball.

Basking in the crowds’ adoration, his guard probably down, Eisenhower replied, within reporters’ earshot, that he had, “under the assumed name of Wilson.”

He added that it was “the one secret of my life.” (He also carped, “What the hell has happened to the pitching since I went away to the war?”)

A few days later, during a visit with his mother in Abilene, Ike elaborated on these comments, explaining to The Associated Press that he had taken “any job that offered me more money” in preparation for college, but that he “wasn’t a very good center fielder.”

However, Eisenhower came to realize — or was convinced to do so by publicity-conscious advisers — that further chatter about his Kansas baseball career before playing sports at West Point had the potential to besmirch his sterling reputation. (One can imagine what modern-style opposition researchers could have done with this information during the 1952 campaign, had they followed the warlike maxim of attacking your adversary’s strengths.)

The Eisenhower Library houses a 1961 notation by his devoted longtime secretary, Ann Whitman, that “DDE did play professional baseball one season to make money” and that he made “one trip under an assumed name.” Another note sets down the ex-president’s private order that “inquiries should not be answered concerning his participation in professional baseball — as it would necessarily become too complicated.”

Nevertheless, in 1948, Ike’s tart sense of pride in his youthful athletic prowess overcame his self-protective instincts. His grandson David Eisenhower recollects in his 2010 book “Going Home to Glory” that Arthur Patterson, the Brooklyn Dodgers’ ex-publicity chief known as Red, told David that, while watching a game that year at Ebbets Field, Patterson had asked Eisenhower about the rumors, saying he had heard that two “Wilsons” had played in the 1909 Central Kansas League.

“Which Wilson was Wilson,” Patterson boldly asked Ike, “and which was Eisenhower?”

“I was the Wilson who could hit,” Ike shot back, before warning, “That’s between you and me.”