From the newspaper The Daily Inter Ocean Saturday January 12, 1895.
The article continues.
The presidents of the larger universities and colleges of the Northwest held a secret conference at the Auditorium last evening. The meeting grew out of a letter sent of the heads of these institutions by President Smart, of Purdue University, requesting a conference, at which might be considered a number of changes in the present football rules which will prohibit slugging and undue roughness in the game.
It is said that the faculties of the various seats of learning in the West have been aroused on the subject by the change of glaring violations of the rules governing amateur athletics, that have been imputed to Western teams. Prominent Eastern periodicals have been decrying the debasement of college sports beyond the Alleghanies, and according to adopt some vigorous measure to eliminate professionalism was another object of the meeting.
Those were were present were: President William R. Harper of the University of Chicago; Henry Wade Rogers of Northwestern University; Charles K. Adams of the University of Wisconsin; Cyrus Northrup, of the University of Minnesota; A.S. Draper, of the University of Illinois; J.H. Smart, of Purdue University. President Angell, of the University of Michigan did not arrive, as was expected. The discussion was spirited and prolonged until midnight. Several different propositions and rules were introduced.
The following resolution proposed by President Smart was passed:
Resolved, That we call upon expert managers of football to so revise the rules of the game that the liability to injury shall be reduced to a minimum.
The article goes on to list the 11 rules established by these University Presidents regarding player eligibility and violence in football.
So there it is. A guy named Smart got the ball rolling on the Big Ten Conference to end slugging. Ever since Illinois, Minnesota, Northwestern, Purdue, and Wisconsin have been part of the league. Also props to that article for shading Michigan for not showing up.