What team in the NCAA made the most appearances?

Until 1950 the tourney had only 8 teams.

The tournament expanded to 32 teams in 1975, marking the first time that teams could win and advance to a "Sweet 16."

The following are the top five teams by number of times each team has advancedto the Sweet 16from 1975 through 2013 (39 years):

25 - North Carolina
23 - Duke
22 - Kentucky
20 - Kansas
19 - Louisville