Which American singer-songwriter who collaborated with Shel Silverstein had a number one single in 1985?
The Highwaymen (country supergroup): The Highwaymen was a country music supergroup composed of four of the genre's biggest artists well known for their pioneering influence on the outlaw country subgenre: Johnny Cash, Waylon Jennings, Willie Nelson, and Kris Kristofferson. The Highwaymen (country supergroup):  Their Columbia works produced three chart singles, including the number one "Highwayman" in 1985. Kris Kristofferson:  Kristofferson composed his own songs and collaborated with Nashville songwriters such as Shel Silverstein.
Kris Kristofferson