Actually commission meetings?
1931- Chicago.
1936- New York, upstate New York, Genovese member's horse farm.
1941- New Jersey.
1943- Emergency Meeting, ?
1946- Chicago. The Havana Conference was not a Commission meeting, but important topics were discussed there.
1950- Emergency meeting Miami, Florida.
1951- New York, The Village. It is vague and could be any number of locations, but definitely near New York City or in one of the boroughs.
1956- Joe Barbara house South West New York. The 1957 meeting was not a commission meeting, but an important meeting for all the families since the turmoil in New York City, Frank Costello, Frank Scalise, and Albert Anastasia.
1959- Emergency meeting, New Jersey, Angelo Bruno installed as boss of Philadelphia.
1961- Unknown, the last time all Commission members meeting in one place at the same time, except for Vito Genovese who was locked up.
1966- New York, Lucchese members beach house, and Detroit. Chicagos Tony Accardo, and Salvatore Battaglia, fill in for Sam Giancana. Gaspare DiGregorio represented the Bonannos, but was removed from acting boss and Paul Sciacca was installed.
1971- Chicago, and New York.
1974/1975- Special meeting, New York City
1976- California, New York City.

There are alot of mini commission meetings and 1978 to 1980 was hectic. Then you had Paul Castellano calling for commission meetings for trivial things mainly construction projects.