Such small numbers were common during the tournament's infancy partly because of the National Invitation Tournament (NIT). Established a year prior to the NCAA tournament and operated by the Metropolitan Intercollegiate Basketball Association (MIBA), the NIT quickly gained esteem for its locale in exotic New York City. Both tournaments existed amicably for many years. Hoops hounds delighted in being able to choose which to follow, though restrictions and team preferences proved detrimental to determining a definitive national champion until 1975.
The ensuing years saw the NCAA championship expand in popularity and scope thanks to several factors. Publicity grew as more games were televised; teams were added--the tournament now supports 68; seeded teams and brackets provided an interactive experience for die-hards and casual fans alike; and it became the authority on which team claims the title of national champion. Gradually, it evolved into an institution, regarded by many college basketball connoisseurs as the only tournament. The NCAA championship tournament now boasts a fanbase over 700,000 and is regularly held in stadiums able to seat more than 40,000 spectators. As for the NIT, it was absorbed by the NCAA in 2005.
Exactly what turned a small, second-tier tournament into a basketball behemoth is somewhat uncertain. Aside from the obvious media touchstones, something about the NCAA championship tournament managed to resonate with sports fans in a way that few competitions have. The term March Madness may not have been used in conjunction with the NCAA until 1982, but the sentiment behind such fervent fanaticism existed long before. And clearly, it's not going anywhere.