Now solidly in the Presbyterian fold, Breckinridge began to follow in the footsteps of his brother John, criticizing Roman Catholicism in a number of his speeches and publications. There were many Catholics in Baltimore. He sponsored and edited two "thoroughly Protestant" journals – the "Baltimore Literary and Religious magazine" and the "Spirit of the XIX Century". A year-long tour of Europe with his wife that began in April 1836 deepened his disdain for the denomination; he opined that most of the continent's ills could be traced back to Catholic "superstitions." A particularly harsh missive against a Catholic who worked in the county almshouse drew an indictment for libel in 1840. The trial ended in a hung jury that voted 10–2 in favor of acquittal. Though displeased that he could not obtain a unanimous acquittal, Breckinridge continued undaunted. In 1841, he published several of his anti-Catholic articles as "Papism in the XIX Century in the United States".