"I Thought About You" is a 1939 popular song composed by Jimmy Van Heusen with lyrics by Johnny Mercer. It was one of three collaborations Van Heusen and Mercer wrote for the then recently established Mercer-Morris publishing company, started by Mercer and former Warner Bros. publisher Buddy Morris. The other two were called "Blue Rain" and "Make with the Kisses". "I Thought About You" was by far the most popular of the songs.
The lyrics were inspired by Mercer's train trip to Chicago. Mercer has said about the song:
"I can remember the afternoon that we wrote it. He [Van Heusen] played me the melody. I didn't have any idea, but I had to go to Chicago that night. I think I was on the Benny Goodman program. And I got to thinking about it on the train. I was awake, I couldn't sleep. The tune was running through my mind, and that's when I wrote the song. On the train, really going to Chicago."
The song has become a jazz standard, having been performed by numerous jazz artists including: