Orestes Brownson (1803–1876) 
Editor of Brownson's Quarterly Review
Brownson was one of the best known American intellectuals of the nineteenth century. A native of Vermont, his religious affiliations shifted from Presbyterian to Universalist to Transcendentalist, before converting to Catholicism in 1844.
Links
Books
The American Republic (amazon.com)
The American Republic (full text)
P. Carey, Orestes A. Brownson: American Religious Weathervane
Review of P. Carey, Orestes A. Brownson, by David J. Voelker
T. Ryan, Orestes A. Brownson: A Definitive Biography