Answer by taking a quote from the following article:

Sandman (Wesley Dodds) is a fictional character, a superhero who appears in American comic books published by DC Comics. The first of several DC characters to bear the name Sandman, he was created by writer Gardner Fox and artist Bert Christman. Attired in a green business suit, fedora, and gas mask, the Sandman used a gun emitting a sleeping gas to sedate criminals. He was originally one of the mystery men to appear in comic books and other types of adventure fiction in the 1930s but later was outfitted with a unitard/cowl costume and developed into a proper superhero, acquiring sidekick Sandy, and founding the Justice Society of America.

Artist Bert Christman and writer Gardner Fox are generally credited as co-creating the original, Wesley Dodd version of the DC Comics character the Sandman. While the character's first appearance is usually given as Adventure Comics No. 40 (cover-dated July 1939), he also appeared in DC Comics' 1939 New York World's Fair Comics omnibus, which historians believe appeared on newsstands one to two weeks earlier, while also believing the Adventure Comics story was written and drawn first. Each of the two stories' scripts were credited to the pseudonym "Larry Dean"; Fox wrote the untitled, 10-page story in New York World's Fair #1, while he simply plotted, and Christman scripted, the untitled, six-page story, generally known as "The Tarantula Strikes", in Adventure #40. Creig Flessel, who drew many early Sandman adventures, has sometimes been credited as co-creator on the basis of drawing the Sandman cover of Adventure #40, but no other evidence has surfaced. Following these two first appearances, the feature "The Sandman" continued to appear in the omnibus Adventure Comics through No. 102 (Feb-Mar 1946). One of the medium's seminal "mystery men", as referred to at the time, the Sandman straddled the pulp magazine detective tradition and the emerging superhero tradition by dint of his dual identity and his fanciful, masked attire and weapon: an exotic "gas gun" that could compel villains to tell the truth, as well as put them to sleep. Unlike many superheroes, he frequently found himself the victim of gunshot wounds, both in the Golden Age and in stories in DC's modern-day Vertigo imprint, and he would continue fighting in spite of his injuries. In his early career, Dodds (the character's surname was given as "Dodd" in his first four appearances; he became "Dodds" in Adventure Comics #44) was frequently aided by his girlfriend, Dian Belmont, who is aware of his dual identity. Unlike many superhero love interests, Belmont was often, though not always, portrayed as an equal partner of the Sandman, rather than a damsel in distress. Later stories would reveal that the two remained together for the duration of their lives, though they never married. The Sandman was one of the original members of the Justice Society of America when that superhero team was introduced in All Star Comics No. 3, published by All-American Comics, one of the companies that would merge to form DC. In Adventure Comics No. 69 (December 1941), Dodds was given a yellow-and-purple costume by writer Mort Weisinger and artist Paul Norris, as well as a yellow-clad kid sidekick, Sandy the Golden Boy, nephew of Dian Belmont. Later that year, the celebrated team of Joe Simon and Jack Kirby took over this version of the character. In 1942, Dodds enlisted in the U.S. Army and served as an anti-aircraft gunner during World War II. CANNOTANSWER

What was special about Sandy the Golden Boy?

nephew of Dian Belmont.