Southern Conf was first to use it in 1980-81 season.
1982 for B1G for example:
https://www.nytimes.com/1982/05/04/sports/big-10-basketball-moves-on-3-point-experiment.html
Big 8 first used it in 1986-87.
Different conferences also had different distances. The line was as close as 17 ft 9 inches in the Atlantic Coast Conference, and as far away as 22 ft in the Big Sky.
Edited by FIJItiger at 14:35:43 on 05/22/20