During the early years of the Green Bay Packers, Turnbull helped convert the team from a privately held franchise to a publicly owned, non-profit corporation.

He also helped the team through multiple financially challenging periods, which saw him identified as part of The Hungry Five, a group of early Packers supporters.

[3][6] Turnbull was an early fan of the Green Bay Packers[7] and was acquainted with its two founders, Curly Lambeau and George Whitney Calhoun.

[10] The Packers were set to play a team from Duluth, Minnesota, on Thanksgiving; however, 12 straight hours of rain threatened to cancel it.

[2] Turnbull convinced the Packers to play the game, even though they would lose a significant amount of money, by promising to rally local business leaders to support the team.

[7] Turnbull fulfilled his promise, organizing a stock sale that raised $5,500 and converted the Packers into a publicly owned, non-profit football team.

His primary contribution as president was helping to keep the Packers in Green Bay during a time when the National Football League (NFL) was paring its member teams down to those located in large cities.

[13][14] Turnbull was active in many local civic institutions, including as the founder and first president of the Oneida Golf and Riding Club.

[14] He was informally identified as part of The Hungry Five, a nickname given by Arch Ward, a writer for the Chicago Tribune, to five of the early Green Bay business leaders who supported the Packers.

[9][13][15] His contributions include the organization of the Green Bay Football Corporation, leading the first stock sale, and raising additional funds during periods of financial difficulties.

[12][13] He also provided leadership as the first president of the corporation, especially when representing the Packers during NFL meetings and the drafting of the League's constitution and by-laws.