According to Sopranos; A Family History, Giacomo Michael Aprile, Sr. was born in 1955, was a close friend and contemporary of Tony Soprano and they came up through the ranks of the DiMeo Crime Family together. Jackie's older brother, Richie Aprile, also stepped up in the same crime family. Jackie was also the brother of Liz La Cerva and thus the uncle of Adriana La Cerva. Jackie and Tony, along with Silvio Dante and Ralph Cifaretto, were in a minor-league crew as kids. Around this time, Jackie had the idea to rob a card game held by then-capo Feech La Manna and, in Ralph's words, "step up to the A-league." Ralph contracted gonorrhea and was unable to rob the card game. However, Tony, Jackie and Silvio took it down. Although they had to give back some of the money, Tony, Jackie and Silvio were on the fast track to being made men.
Jackie's star rose considerably in the intervening years, during which he started a family. He married Rosalie Aprile, and they had three children together. Jackie never wanted his son Jackie Aprile, Jr. to get involved in his father's business, despite his success. At some point Jackie served time in prison in Lewisberg with the later identified informant Fabian "Febby" Petrulio. Tony said that Jackie did 'a couple of counts' in jail, suggesting that although he served jail time it was not a significantly long sentence, hence his quick ascension to Acting Boss for his ability to avoid jail time by working the system and surviving. He was considered to be an all-powerful figure in the crime family, and by the mid-1990s his influence, power and success continued to expand as he assumed more and more responsibilities as Acting Boss while Ercole 'Eckley' DiMeo went on trial and then to prison for life in 1995, becoming Acting Boss of the Family. This greatly aggrieved Corrado "Junior" Soprano, who had believed with his brother Johnny dead and DiMeo in prison forever that he would become Boss. Known as a well-respected leader of the family, people say that Jackie's reign over the DiMeo Family was peaceful. Although Jackie was officially Boss of the family, out of respect to "The Old Man" DiMeo, Aprile referred to himself as the "Acting Boss," even though he had wielded de facto control of the family since 1995.
However, Jackie's reign was short lived. Aprile was diagnosed with stomach cancer and first hospitalized in late 1998 and by early 1999 (season one of The Sopranos) was clearly fading fast. He made Tony his street boss so he could collect for him. For a brief time in early 1999, Jackie seemed to have recovered and was out on the streets again. In "46 Long" Jackie mediated a dispute between Tony and Junior. However, the cancer had recurred and by "Denial, Anger, Acceptance" he was admitted to hospital and his Acting Underboss Tony Soprano, and Capos visited him there to pay respects. Gradually, Tony Soprano gained more control over the DiMeo family as Jackie's condition worsened. Tony brought a dancer from the Bada Bing! club to entertain Jackie in his hospital bed. Tony later made a promise to him that he would keep his only son Jackie Aprile, Jr. out of the family business. Jackie died of cancer in August 1999 (noted in a news broadcast playing in the background in the episode "I Dream of Jeanie Cusamano"). A war between Junior Soprano and Tony Soprano was anticipated, but immediately following Jackie's death, Tony met with his uncle and "let" him become Acting Boss. However, since Eckley DiMeo and Jackie Aprile had Tony picked to be Acting Boss, and the captains Raymond "Buffalo Ray" Curto, Lawrence "Larry Boy" Barese, and Jimmy Altieri wanted Tony to be their leader, Junior was actually the Boss only in name. Tony was the one who actually ran things but Jackie was more successful than him. He was the top earner. He had bookmaking cuts in hotels, prostitution, sanitation, cocaine and heroin.
It is thought that Jackie Aprile Sr. is loosely based on real New Jersey mobster and Acting Boss Giacomo "Jake" Amari, who also died of cancer and whose death similarly sparked a power struggle within the DeCavalcante crime family.
A news reporter who reported the news of his death mistakenly reported that Jackie had become Boss in 1997, though the events of To Save Us All From Satan's Power show that he had gained power in 1995.