There are a number of well researched and sourced books you can read about the history of college sports, the history of the NCAA and the evolution of the concept of amateurism (e.g., Sack & Staurowsky, Zimbalist, Byers).
You can also search through various legal journals to find numerous articles analyzing issues like amateurism or antitrust law applicability to the NCAA, which discuss what was said by the schools and folks like Walter Byers at the time athletics scholarships were made legal in 1956.
Sack and Staurowsky also summarized some of this research in the amicus brief they submitted to the Supreme Court during the Alston case. Per page 10:
For fifty years after enacting its first set of bylaws in 1906, the NCAA forbade athletic scholarships, called “grants-in-aid,” deeming them “pay” that violated traditional amateur norms. Pet. App. 141a-142a. However, in the absence of an enforcement regime, many schools sought to gain a competitive advantage by compensating players under the table, giving them make-work jobs, or providing them loans that did not require repayment. In 1956, after tolerating unauthorized payments for decades, the NCAA finally permitted schools to offer grants-in-aid covering tuition, fees, room, board, and incidental costs. O’Bannon II, 802 F.3d at 1054.
What the NCAA previously said was a blatant violation of amateur ideals became part of the fabric of college sport, with schools providing each scholarship athlete a grant-in-aid package that, depending on the institution, totaled tens of thousands of dollars every year. For the rest of the 20th century, the NCAA tinkered with the grant-in-aid as an acceptable form of pay, for instance eliminating incidental expenses in 1976, Pet. App. 69a, and establishing a Student Assistance Fund in 1991 to help athletes with exceptional financial needs.