information:classification
20th century

In the early 20th century, the university outgrew its buildings and the trustees began to search for a new home. Developing Clifton for the university was too costly, and 30 acres (12 ha) of the estate had to be sold to the city as public park. A solution was achieved by a team of prominent locals who acquired the estate in north Baltimore known as the Homewood Campus of Johns Hopkins University. On February 22, 1902, this land was formally transferred to the university. The flagship building, Gilman Hall, was completed in 1915. The School of Engineering relocated in Fall of 1914 and the Zanvyl Krieger School of Arts and Sciences followed in 1916. These decades saw the ceding of lands by the university for the public Wyman Park and Wyman Park Dell and the Baltimore Museum of Art, coalescing in the contemporary area of 140 acres (57 ha).

Prior to becoming the main Johns Hopkins campus, the Homewood estate had initially been the gift of Charles Carroll of Carrollton, Maryland, a planter and signer of the Declaration of Independence, to his son Charles Carroll Jr. The original structure, the 1801 Homewood House, still stands and serves as an on-campus museum. The brick and marble Federal style of Homewood House became the architectural inspiration for much of the university campus versus the Collegiate Gothic style of other historic American universities.

In 1909, the university was among the first to start adult continuing education programs and in 1916 it founded the nation's first school of public health.

Since the 1910s, Johns Hopkins University has famously been a "fertile cradle" to Arthur Lovejoy 's history of ideas.

Since 1942, the Johns Hopkins Applied Physics Laboratory (APL) has served as a major governmental defense contractor. In tandem with on-campus research, Johns Hopkins has every year since 1979 had the highest federal research funding of any American university.

Professional schools of international affairs and music were established in 1950 and 1977, respectively, when the Paul H. Nitze School of Advanced International Studies in Washington, D.C., and the Peabody Institute in Baltimore were incorporated into the university.