The above line “Success Looked For Henry David Thoreau not because he was too busy” is my own original quote; meant to ridicule those who simply attributed the popular quotation: “Success usually comes to those who are too busy to be looking for it.” to him
The fact is that quote is NOT by Henry David Thoreau.
It is said to be adapted from a line published in Locomotive Engineers Journal, Volume 76.
The actual line from the journal is: “Success usually comes to those who are too busy to look for it” which is on page 711. [source]