Presidents Carrick through Holt were presidents of the campus in Knoxville and any branches and subdivisions. Presidents Boling through Johnson served as presidents of the University of Tennessee system, devised in 1968 to reflect the need for the constituent institutions to have an administration in place at the campus. President Wade Gilley reorganized the institution in 1999, placing UT Knoxville, the UT Medical Units, the Agricultural Institute, the Space Institute, and the Institute for Public Service into one institution—the University of Tennessee. The president headed this combined institution, and the chancellor’s position at Knoxville was abolished. UT at Chattanooga and UT at Martin functioned as branches, with chancellors who reported to the president. The title “Chancellor” was restored at Knoxville in 2003, and Presidents Petersen and those who followed him were again presidents of the University of Tennessee system.