Doobie Brothers guitarist and lead singer Tom Johnston wrote this song, which they played live for three years before recording. Johnston told Songfacts
: "Generally I write the music first, and sometimes I have a devil of a time getting the words. Sometimes they come right away, and sometimes it's like pulling teeth. We played 'Long Train Runnin'' for three years before it got recorded, and it got called several different names, and most of the time I would make up the words as we were playing the song.
I think we started playing that in the Chateau, so that would have been around 1970-71. And it got called 'Osborne,' it got called 'Parliament,' it got called a lot of things. It was just anything to put down on the set list so we'd know what song it was, but it didn't have any words - I would just make up the words as we played the song. So they might be nonsense - might be? They're definitely nonsensical. And it continued that way until Teddy [producer Ted Templeman] heard it and said, 'You should cut that.' And I said, 'Oh, man, this is just a throwaway song.' I didn't think it was any big deal. I didn't think it had any great merit as far as the chords and everything went, because it seemed too simplistic to me. But I was wrong, and wrote the words in the bathroom, which happened a lot down there. I wrote the words sitting in the bathroom at Amigo Studios in Burbank, which doesn't exist anymore. But that's where we did all those records, and it was owned by Warner Brothers. So it was like a last-minute deal, and then I came in and sang, and boing, the record was done."