In 1874, Pope Pius IX established the Vicariate Apostolic of Brownsville and named Bishop Dominic Manucy its vicar apostolic. The new church division included all the settlements south of the Nueces River to the Rió Grande. After only a brief stay in Brownsville, Bishop Manucy moved to Corpus Christi. During his decade of service in Corpus Christi, Bishop Manucy built nine churches and three others were under construction when he was called to serve as the Bishop of Mobile, Alabama.
Pope Leo XIII named San Antonio Bishop Jean Claude Neraz as administrator of the Vicariate of Brownsville. Bishop Neraz appointed Father Jaillet as Vicar General and because the bishop was already too busy with his own diocese, Father Jaillet served as de facto administrator until 1890 when the pope named Peter Verdaguer the second bishop of the Vicariate Apostolic of Brownsville. Bishop Verdaguer moved his residence from Corpus Christi to Laredo where he concentrated his efforts. Still, it was under his tenure that Spohn Hospital was established and that the Sisters of Charity of the Incarnate Word came to Corpus Christi from San Antonio to open the hospital.