I do know that the voting had to be done early in the season. The Cubs scheduled three giveaways of a seven card package of members of the All-Century team. The first set was handed out on May 15. That meant about a month to select the team and then print up the 20,000 sets.
The selections were fairly predictable...
...You got Tinker, and Chance, but no Evers. Teammate Three-Fingers Brown was also selected.
...Grover Cleveland Alexander was selected, though his best years were with the Phillies.
...From the pennant-winning teams of the last '20s and '30s you get Phil Cavarretta, Charlie Grimm, Stan Hack, Gabby Hartnett, Billy Herman, and Hack Wilson.
...The '69 Cubs had Banks, Jenkins, Santo, and Williams
...Bruce Sutter was the lone representative from the late '70s.
...From the '80s came Ryno, Lee Smith, and Andre Dawson.
...The most recent players to make the team were both active with the Cubs in 1999, Mark Grace and Sammy Sosa.
Here's a look at all 21 cards in a 3x7 tile