Paul Ricca boss and representative 1932 - 1943 (imprisoned 1944 - 1946)

From 1947 until 1972 Ricca was the Outfits top boss and besides guys like Accardo, Giancana and Battaglia being the official representatives during certain time periods and having the right to vote on the round table, still Ricca's opinion and final word held more weight to the other family bosses than the vote of his "chief executive", which in fact was often created previously by being consulted with Ricca first. Giancana couldve killed Bonanno with the blink of an eye but Ricca didnt approve it.

This means that Ricca was at the top of the organization for about 36 years.

Now, lets look at Accardo...boss and representative 1947 - 1956

In 1957 Accardo became Giancanas senior advisor and was ALMOST on the same level as Ricca, but he rarely dealt with commission stuff by being mostly concentrated on the Outfit and its leading admin. So I personally dont see Accardo as official representative for Chicago or having Ricca's last word from 1957 until 1972. Yes, Accardo was an advisor and sometimes accompanied Giancana on commission meetings, like the one in Miami, but ONLY as senior advisor with previous experience.

When Ricca died in 1972, Accardo became the top boss either from 72 until 1983/84 or until his death in 1992. In 1976/77 Accardo presided over induction ceremonies but in 1983 it was up to Aiuppa.

This means that Accardo was at the top for either 21 years or 29 years, depending on how we look at the situation.

As we can see, Ricca was probably the longest serving family boss for the Chi mob.

And we also must not forget DiFronzo....he had similar career as Riccas or Accardos