Orestes Augustus Brownson (September 16, 1803 – April 17, 1876) was an American intellectual, activist, preacher, labor organizer, and writer.

Sylvester Brownson died when Orestes was young and Relief decided to give her son up to a nearby adoptive family when he was six years old.

The adopting family raised Brownson under the strict confines of Calvinist Congregationalism on a small farm in Royalton, Vermont.

He became the editor of a Universalist journal, Gospel Advocate and Impartial Investigator, in which he wrote about his own religious doubt and criticized organized faiths and mysticism in religion.

[7] Brownson originally offered use of the Boston Quarterly Review as a literary vehicle for the Transcendentalists; they declined and instead created The Dial.

[10] In fact, Van Buren himself is said to have "blamed [Brownson] as the main cause of his defeat" because the Boston Quarterly Review had recently promoted socialist ideas.

In the spring of 1843, rumors spread that Brownson was considering converting to Catholicism, especially when he met with the Roman Catholic Bishop of Boston.

[15][16] Brownson soon renounced what he now considered the errors of his past, including Transcendentalism and liberalism, and devoted himself to writing articles dedicated to converting America to Catholicism.

His unruly enthusiasm resulted in letters from local Catholic journalists and even the bishop of his diocese requesting that he cease leveling such harsh criticisms.

He became increasingly lonely as a result of his being shunned from Boston communities, so he moved the Review and his family to New York in 1855, where he revived his interest in Catholic political philosophy.

[30] His remains were subsequently transferred to the crypt of the Basilica of the Sacred Heart at the University of Notre Dame, where his personal papers are also archived.

He was invited to New Orleans in 1855 by the publication Le Propagateur, because he was viewed as a figure whom both Protestants and Catholics might enjoy hearing from, because of his multiple political and religious associations during his life.

[31] In 1850s, among his many intellectual contributions, in the midst of Irish and German immigration debate and related nativist moral panic, Brownson introduced the term "Americanization" into the public discourse while delivering a lecture, "Church and the Republic", at St. John’s College, future Fordham University.

[32][33] His attempts to harmonize ethnic immigrant identities with American democratic tradition without social and cultural homogenization are considered as an early move in the direction of multiculturalism.

[37] Edgar Allan Poe refers to Brownson in his Autography series, calling him "an extraordinary man," though he "has not altogether succeeded in convincing himself of those important truths which he is so anxious to impress upon his readers.

"[38] He is also mentioned in Poe's story "Mesmeric Revelation," referring to Brownson's 1840 novel Charles Eldwood; or, The Infidel Converted.

While reviewing Brownson's biography penned by Arthur M. Schlesinger Jr., Henry Steele Commager noted that: "In his day Orestes Brownson was respected and feared as were few of his contemporaries; European philosophers regarded him with hope; American politicians enlisted his vitriolic pen; denominations competed for his eloquence; and when he listed himself among the three most profound men in America there were those who took him seriously.

"[39] Peter J. Stanlis has pointed out that "In the generation following the founding fathers of the American republic, Orestes Brownson, together with John C. Calhoun, was probably the most original and profound political thinker of the nineteenth century.

"[42] Brownson's brother, Oran, joined the Church of Jesus Christ of Latter-day Saints about the same time Orestes became a Roman Catholic.