“[T]he human person has a right to religious freedom,” which is described as “immunity from coercion in civil society.” This principle of religious freedom “leaves untouched traditional Catholic doctrine on the moral duty of men and societies toward the true religion.” In addition, this right “is to be recognized in the constitutional law whereby society is governed and thus it is to become a civil right.”
Pius IX (1846-1878) definition
Syllabus of Errors
Pope Pius IX had written a document called the Syllabus of Errors. The Syllabus was made up of phrases and paraphrases from earlier papal documents, along with index references to them, and presented as a list of “condemned propositions”. It does not explain why each particular proposition is wrong, but it cites earlier documents to which the reader can refer for the Pope’s reasons for saying each proposition is false.
“Among the statements included in the Syllabus are
“[It is an error to say that] Every man is free to embrace and profess that religion which, guided by the light of reason, he shall consider true… .”
“[It is an error to say that] In the present day it is no longer expedient that the Catholic religion should be held as the only religion of the State, to the exclusion of all other forms of worship… .”
“[It is an error to say that] Hence it has been wisely decided by law, in some Catholic countries, that persons coming to reside therein shall enjoy the public exercise of their own peculiar worship.”
About the only way I could get quick information about 19th century Catholicism was here, and it lists significant events.
The reason I rely on Wikipedia quite frequently is that the main entry on the Catholic Church is accurate.