After the Godfather II, some dates don't seem to match. Starting with the Don (Vito). He looks to be an old man of about 70, but according to the flashback sequences, we know he was 9 when he arrived at Ellis Island in 1901. Michael didn't eliminate the other heads of the five families until 1950 (according to the senate hearing) after his father's death. So at best, Don Vito would've been 58 years old. At Anthony's communion celebration in 1958, Kay tells Michael he promised that the "family" would be "legitimate in 5 years...that was 7 years ago". That would make the year 1951 but that can't be right since they were already married, with Anthony(3) when Don Vito died. Michael made that statement to her after his return from Sicily in what had to be 1949. We know this because Michael killed Sollozzo and McCluskey in 1947 and had to leave for at least a year. But when he saw Kay again for the first time, he told her he'd been back, "a year, maybe more, I think." Just a little something to think about...