I couldn't find the chords for this song anywhere, so I thought I'd put them up.
I'm surprised I couldn't find this, maybe I have the name of the song wrong! Arlo
Guthrie did a great cover of this song at Woodstock in 69. he played it with a 12
string so it may sound a little different. Chords might be wrong, but it sounds
good to me. I play it with a capo on the second fret and it seems true to the
version of the song I have, but it's Bobby, so it may change depending on which
version you have. 
Standard tuning
Capo II

C
I'm walking down the line,
F
I'm walking down the line,
C
I'm walking down the line,
F
My feet will be a'flyin',
C              F              C      
I'll tell you'bout my troubled mind.

This pattern continues for the rest of the song.