It's often assumed that Big Paul only began to take over the family around 1975 as Carlo's health failed and he needed someone to manage the family day to day. But this FBI report from February 1967 - long before Carlo had any major health woes, arguably at the height of his power - says differently:
"On February 28, 1967, NY T-25 advised that a meeting was held on Monday night, February 27, 1967, at the residence of LEO GRILLO, 1235 54th Street, Brooklyn, New York, at which approximately 19 members of the Gambino 'family' were present. JAMES FAILLA was introduced as the "Caporegima" for half of the old regime of JOSEPH GENNARO.
The meeting was presided over by PAUL CASTELLANO, who advised the group that he was "Acting Boss" for CARLO GAMBINO in all matters. CASTELLANO pointed out that because of increased pressures by the Federal Bureau of Investigation and other law enforcement agencies on GAMBINO, CASTELLANO would act more often on LCN matters for the "boss."
In addition, ANIELLO DELLACROCE was present and was introduced to the group as UNDERBOSS in the "family."
JOSEPH GALLO was also present and he was introduced as the acting "Consulieri" for the "family" because of the illness and lack of mobility on the part of JOSEPH RICCOBONO.
CASTELLANO stated there was now a closer coordination of the "family" membership and pointed out that in addition to SABBATO MURO being excluded from the "family", ANDREW TORREGROSSA, and his son, JOHN, were eliminated from the "family." CASTELLANO pointed out that all members were to have nothing to do with the BONANNO "family" membership, and stated that their leadership is still "up in the air." Informant advised that the COLOMBO "family" was entirely subservient to CARLO GAMBINO.
CASTELLANO also pointed out that there would be no trouble with the LUCHESE "family" in view of the relationship between GAMBINO and LUCHESE, and in view of the serious illness of THOMAS LUCHESE.
According to the informant, CASTELLANO indicated that CARLO GAMBINO, at the present time, was the most powerful "Boss" in LCN."
It seems Paul de facto ran the family for almost a decade before Carlo died, and in a sense, the Castlleno reign can be looked at as spanning from 1967 to 1985 rather than it just being that Castellano was picked out of the blue in 1975 because Carlo was sick and he was his brother-in-law. It would seem that Castellano's leadership as Acting Boss from 1967 onward impressed Carlo. That, combined with his genteel manner and the fact that Dellacroce seemed to attract the attention of the Feds (having been arrested and even in jail when Carlo died) might've influenced Carlo picking Paul, moreso than any nepotism.
http://www.maryferrell.org/showDoc.html?...99&tab=page
