In a move to expand educational opportunities at Virginia Tech, the board of visitors made participation in the Corps completely voluntary starting in 1964. However, participation in ROTC continued to also require Corps membership. The Vietnam War period saw unrest on campus outside the Corps ranks. In 1970 demonstrations were conducted with the aim of halting Corps drill. Cowgill and Williams Hall were occupied and over 100 students were arrested. Other incidents occurred including the suspected arson of an on-campus building. Civilian-cadet relations were at an all-time low. Throughout all of this, the Corps maintained discipline and high esprit.