Contrary to popular legend, "American Pie" was not the name of the plane Holly, Valens, and Richardson went down in. The craft was a single-engine chartered plane and would therefore only have a number as identification (in this case, N3794N). In McClean's own words: "The growing urban legend that 'American Pie' was the name of Buddy Hollys plane the night it crashed, killing him, Ritchie Valens and the Big Boppper, is untrue. I created the term."
The other popular myth surrounding the phrase is that the singer dated a Miss American contestant. (Which would have been an impressive feat indeed at thirteen!) In any event, this urban legend fails to explain why McLean would use such a relationship to describe the tragedy.
Drove my Chevy to the levee
But the levee was dry
Most students of the song see this merely as another metaphor for the death of the American dream. A Chevy was a very popular car among youth. The levee, for towns that had them, was a popular gathering place for teens who wanted to hang out without adult supervision.
And them good old boys were drinkin' whiskey and rye
Singin' "This'll be the day that I die."
"This'll be the day that I die."
A play on the phrase "That'll be the day that I die," made popular by Buddy Holly's hit recording "That'll Be The Day." There's no evidence that "them good old boys" -- Holly and Richardson were both born in Texas, which may have prompted that phrase -- were drinking whiskey or rye the night of the crash.
An alternate theory holds that, since rye IS a kind of whiskey, McLean is actually singing "drinking whiskey IN Rye." Ths singer's home was New Rochelle, which did indeed feature a bar called "The Levee." Allegedly, this bar shut down or "went dry," causing patrons to drive across the river to Rye, NY.