The eldest son of real-estate businessman Fred Trump Sr., he fell out of his father's favor when he chose to become an airline pilot, leading to his younger brother Donald inheriting the family business.

By the early 1970s, he could no longer function as a pilot due to his alcoholism, a condition which also contributed to his fatal heart attack.

[6]) Fred Trump Jr. became president of the fraternity and graduated with a Bachelor of Arts in business, also completing Reserve Officers' Training Corps and entering the Air National Guard as a second lieutenant.

[11] Fred Jr. left the company to pursue his dream of being a pilot, quickly being accepted at Trans World Airlines, which created tension with his father.

[12] According to Fred Jr.'s daughter, Mary L. Trump (born 1965), her grandfather "dismantled him by devaluing and degrading every aspect of his personality."

[13][14][15][16] By 1970, after a series of domestic incidents, Clapp asked Trump to leave their home and arranged for Fred Sr. to change the locks.

Donald Trump, who since 1976 has spoken publicly of his own abstinence from alcohol,[23][24] initially cited the formative influence of their father's teetotalism,[25][26] but later shifted credit to the adult experience with his brother, saying:Every day he lectured me, "Look at the mess I'm in.

Donald, who later said he "was angry because they sued,"[12] suspended the medical benefits for Trump children, as well as Fred III's infant son.

[31] Mary’s lawsuit was rejected by a New York State Court, citing that she had signed agreements that removed her ability to sue but granted her more than $2.7 million.

[33] In 2019, Donald Trump said about his brother's death:[34] I do regret having put pressure on him [as running the family business] was just something he was never going to want.