Strumming Pattern For American Pie

Each verse of "American Pie" has 3 distinct sections:

For example in verse 1:

   Part 1

A long long time . . .

.....

. . . . happy for a while.

   Part 2

But February made . . .

.....

. . . . one more step.

   Part 3

And I can't remember . . .

.....

. . . . the music died.

Each section has a disctinct 'feel' and rythm (although Parts 1  and 3 are similar).

Don't  try to barge through the 3 sections of each verse with the same approach.

Don McClean also messes around alot with the meter in different verses with stressed syllables coming at different point in the lines. 

The real guts of this song is the lilting melody of the lyric.  No matter how technically correct the backgound migh  be, if the vocal isn't right - - it won't have the right stuff.  For what it's  worth, get the vocal right and the music pattern will follow.