Seeking to unify a geographically scattered school and enable it to participate in the development of the city, school president Lemuel Murlin arranged that the school buy the present campus along the Charles River. Between 1920 and 1928, the school bought the 15 acres (61,000 m2) of land that had been reclaimed from the river by the Riverfront Improvement Association. Plans for a riverside quadrangle with a Gothic Revival administrative tower modeled on the “Old Boston Stump” in Boston, England were scaled back in the late 1920s when the State Metropolitan District Commission used eminent domain to seize riverfront land for Storrow Drive. Murlin was never able to build the new campus, but his successor, Daniel L. Marsh, led a series of fundraising campaigns (interrupted by both the Great Depression and World War II) that helped Marsh to achieve his dream and to gradually fill in the University’s new campus. By spring 1936, the student body included 10,384 men and women.

In 1951, Harold C. Case became the school’s fifth president and under his direction the character of the campus changed significantly, as he sought to change the school into a national research university. The campus tripled in size to 45 acres (180,000 m2), and added 68 new buildings before Case retired in 1967. The first large dorms, Claflin, Rich and Sleeper Halls in West Campus were built, and in 1965 construction began on 700 Commonwealth Avenue, later named Warren Towers, designed to house 1800 students. Between 1961 and 1966, the BU Law Tower, the George Sherman Union, and the Mugar Memorial Library were constructed in the Brutalist style, a departure from the school’s traditional architecture. The College of Engineering and College of Communication were housed in a former stable building and auto-show room, respectively. Besides his efforts to expand the university into a rival for Greater Boston’s more prestigious academic institutions, such as Harvard University and the Massachusetts Institute of Technology (both in Cambridge across the Charles River from the BU campus), Case involved himself in the start of the student/societal upheavals that came to characterize the 1960s.

When a mini-squabble over editorial policy at college radio WBUR-FM – whose offices were under a tall radio antenna mast in front of the School of Public Relations and Communications (later College of Communications) – started growing in the spring of 1964, Case persuaded university trustees that the university should take over the widely-heard radio station (now a major outlet for National Public Radio and still a BU-owned broadcast facility). The trustees approved the firing of student managers and clamped down on programming and editorial policy, which had been led by Jim Thistle, later a major force in Boston’s broadcast news milieu. The on-campus political dispute between Case’s conservative administration and the suddenly active and mostly liberal student body led to other disputes over BU student print publications, such as the B.U. News and the Scarlet, a fraternity association newspaper.

The Presidency of John Silber also saw much expansion of the campus and programs. In the late 1970s, the Lahey Clinic vacated its building at 605 Commonwealth Avenue and moved to Burlington, Massachusetts. The vacated building was purchased by BU to house the School of Education. After arriving from the University of Texas in 1971, Silber set out to remake the university into a global center for research by recruiting star faculty. Two of his faculty “stars”, Elie Wiesel and Derek Walcott, won Nobel Prizes shortly after Silber recruited them. Two others, Saul Bellow and Sheldon Lee Glashow won Nobel Prizes before Silber recruited them.

In addition to recruiting new scholars, Silber expanded the physical campus, constructing the Photonics Center for the study of light, a new building for the School of Management, and the Life Science and Engineering Building for interdisciplinary research, among other projects. Campus expansion continued in the 2000s with the construction of new dormitories and the Agganis Arena.