Shea is born into a poor family in Ireland in 1890. At age 10, he immigrates to America and lives in the infamous Hell's Kitchen neighborhood. At age 30, he is the Ambassador to Canada. He also meets a young Vito Corleone and does business with him by using his olive oil trucks to import whiskey from Canada. He also at this time fathers two sons, James and Danny. By the end of Prohibition, his family is one of the richest in America. He also at this time does business with Robert Moses and expands his empire. By the 1940s, he has begun guiding his sons into political careers, seeing potential especially in James. By the 1950s, James is the Governor of New Jersey and Danny is the Assistant Attorney General of New York. In 1956, he retires to Manhattan.
In the novel, Shea approached the Corleone Family for help. He asks them to get James elected president; in return, James would stop cracking down on organized crime. He and Corleone family consigliereTom Hagen reach a deal that they would get James elected in 1960 and Hagen would become a Congressman. Ultimately, Hagen loses the election, but James is elected president in 1960. Many people suspect vote fraud and demand a recount, but Shea puts a stop to it.