By 1955, Presley had released five singles on Sun Records and was gaining traction through personal appearances across the South and on the nationally broadcast Louisiana Hayride radio show. His popularity in the country music scene grew rapidly; he was voted the number one "up-and-coming" country and western artist in a Billboard disc jockey poll. That same year, Presley’s career took a pivotal turn when Colonel Tom Parker (1909-1997)—an eccentric and savvy promoter with a background in carnivals and a hidden past as an undocumented immigrant from the Netherlands—took over as his manager. Parker quickly orchestrated the sale of Presley’s contract from Sun Records to RCA Victor for $40,000, an unprecedented sum at the time.

Under RCA, Presley began working with producer Chet Atkins to craft a more polished, pop-friendly sound. In 1956, Presley released a string of blockbuster hits including "Heartbreak Hotel," "Don’t Be Cruel," and "Hound Dog." The latter, originally recorded by Big Mama Thornton and written by Jerry Leiber and Mike Stoller, was radically altered in Presley’s rendition. While Thornton’s original was gritty and sexually charged, Presley’s version featured sanitized lyrics that appealed to mainstream sensibilities. This adaptation became a hallmark of white covers of Black R&B songs during the era. Despite the alterations, Presley’s version of "Hound Dog" became a landmark success, spending eleven consecutive weeks at number one and becoming the first single to top the pop, country, and R&B charts simultaneously.

Colonel Parker played a crucial role in shaping Presley’s multimedia empire and cultivating his image as an unprecedented cultural phenomenon. Drawing on his background in traveling carnivals and promotion, Parker orchestrated an aggressive and innovative marketing strategy. He arranged major television appearances, signed lucrative merchandising deals, and secured Presley roles in Hollywood films, expanding his reach well beyond the music industry. Parker effectively turned Presley into a brand, capitalizing on every aspect of his public persona. He licensed Elvis-branded products ranging from clothing to cosmetics, and even launched the now-famous “I Hate Elvis” buttons—cynically cashing in on detractors as well as fans by owning both sides of the cultural conversation.

However, Parker’s management came at a steep cost. He often claimed as much as 50 percent of Presley’s earnings—far above the industry norm—and strictly limited Presley’s public appearances to increase demand. These tactics, while effective in maintaining Presley’s mystique and market value, also led to an isolating and grueling work schedule. Combined with the strain of constant visibility, a relentless film production schedule, and increasing personal pressures, these factors contributed to Presley’s growing dependence on prescription drugs and to his gradual retreat from public life. He often claimed as much as 50 percent of Presley’s earnings—far above the industry standard—and severely restricted Presley’s public appearances to increase demand. These constraints, coupled with Presley’s grueling film schedule and mounting personal pressures, contributed to his growing isolation and eventual dependence on prescription drugs later in his life.

Sales of Presley’s records during this period reached unprecedented heights. "Heartbreak Hotel" sold over a million copies within months of release. The double-sided single "Hound Dog"/"Don’t Be Cruel" sold more than three million copies in one year. Uniquely, both sides of many of Presley’s singles reached the Top 10, a rare feat at the time. "Don’t" and "I Beg of You," "One Night"/"I Got Stung," and "A Fool Such As I"/"I Need Your Love Tonight" all charted highly. Even as late as 1960, "Are You Lonesome Tonight?" reached all three major Billboard charts.

Presley continued to draw from both country and R&B influences throughout his early RCA years. He covered hits such as Joe Turner’s “Shake, Rattle, and Roll,” Lloyd Price’s “Lawdy Miss Clawdy,” the Orioles’ “Crying in the Chapel,” and multiple Little Richard tracks including “Tutti Frutti,” “Long Tall Sally,” and “Ready Teddy.” He also interpreted country classics like Carl Perkins’s “Blue Suede Shoes” and even ventured into pop standards like Rodgers and Hart’s “Blue Moon.”