UTS is the oldest independent seminary in the United States and has long been known as a bastion of progressive Christian scholarship, with a number of prominent thinkers among its faculty or alumni.

In 1893, UTS rescinded the right of the General Assembly of the Presbyterian Church to veto faculty appointments, thus becoming fully independent.

In 1891, Charles A. Briggs, who was being installed as the chair of biblical studies, delivered an inaugural address in which he questioned the verbal inspiration of Scripture.

[11] Among its graduates were the historian of Christianity Arthur McGiffert; biblical scholar James Moffatt; Harry Emerson Fosdick, the pastor of Riverside Church who served as professor during his tenure there; and the Socialist leader Norman Thomas.

The ethos of the settlement house movement called for its workers to "settle" in such neighborhoods in order to learn first-hand the problems of the residents.

[12] Union Settlement still exists, providing community-based services and programs to support the immigrant and low-income residents of East Harlem.

One of East Harlem's largest social service agencies, Union Settlement reaches more than 13,000 people annually at 17 locations throughout East Harlem through a range of programs, including early childhood education, youth development, senior services, job training, the arts, adult education, nutrition, counseling, a farmers' market, community development, and neighborhood cultural events.

As liberalism lost ground to conservatism after the 1960s (while neo-orthodoxy dissipated) and thus declined in prestige, UTS ran into financial difficulties and shrank significantly because of a reduced student base.

[14] On May 9, 2024, UTS's Board of Trustees voted to endorse divestment from "companies profiting from the war in Palestine" and announced that they will be joining the Interfaith Center on Corporate Responsibility.

[18] UTS's campus is located in the Morningside Heights neighborhood of Manhattan, New York City, bordered by Claremont Avenue, Broadway, and West 120th and 122nd Streets.

The building was added to the National Register of Historic Places on April 23, 1980, and parts were made a New York City designated landmark in 1965.

They become intoxicated with liberal and humanistic phrases, are amused at the fundamentalists, and yet basically are not even up to their level...."[20] Referring to Union Seminary, Bonhoeffer noted: "A seminary in which numerous students openly laugh during a public lecture because they find it amusing when a passage on sin and forgiveness ...is cited has obviously, despite its many advantages, forgotten what Christian theology in its very essence stands for" (pp. 309–10).