Such men as Cardinal Gibbons and Archbishop John Ireland of Minneapolis were at the fore-front of the ideas that American Catholics did not have to be obedient to Rome, because the Vatican was "too far away" from the American experience, and that some of the modernist heresies could be incorporated into the Church.
Even though Gibbons denied involvement in the heresy, he was involved, as were many of the Irish bishops in the East. The problem also included the pushing of the separation of Church and State, never an idea supported by Rome.
Pope Leo XIII wrote two documents, and called some of the leaders to Rome for "visits".
His documents can be found on line. Longinqua oceani and the encyclical Testem Benevolentiae Nostrae both warned and chastised the leaders who were creating what we now see-the informed dissenting Church of America.
The entire fallacy of putting the American Dream before living as a "sign of contradiction" in the world has come to a head now in the States. Catholics here are decrying the disobedience of the German bishops. However, there are many bishops in the States who are in disobedience, not standing up against contraception, allowing homosexuals into seminaries, distributing Communion to politicians obviously supporting abortion, and actively supporting the party of death-the Democrats.
The heresy of Americanism is alive and well and festering, ready for an outbreak of schism.