While he continued to announce the existence of his missionary college at Mill Hill and to search for recruits, Herbert Vaughan did not know as yet where he might send them. Cornelius Dowling and three more new priests were still cooling their heels. In May 1870 the founder was in Rome, presenting himself daily at the office of the Cardinal Prefect of Propaganda who finally asked him to consider Labuan and Borneo as a field for his missionaries. Vaughan was inclined to hold out for part of Japan.
It was finally the needs of the American Church that determined the assignment of the first missionaries. For years the Archbishop of Baltimore had been appealing to Rome to consider the needs of the millions of people then being released from slavery and had more recently made his appeal to Herbert Vaughan. Vaughan continued to petition the Pope for a mission field, mentioning, though not volunteering for, the African-American apostolate. The matter was settled when he read the words of the missionary founder, Francois Libermann, that the salvation of African people depended on priests filled with the Spirit of the Lord.
In the autumn of 1871, Pius IX assigned Vaughan’s missionaries to Baltimore in Maryland and granted the founder and his men the title of “Apostolic Missionaries’. The pioneers were Cornelius Dowling, James Noonan, Joseph Gore and Charles Vigneront.
Archbishop Manning came to the College on 17 November 1871 to preside at the departure ceremony. Al those present, including the Dutch builders, kissed the feet and faces of the men about to depart in procession to Mill Hill railway station. The following day the founder and his four missionaries boarded the SS Berlin at Southampton. On 5 December they arrived in Baltimore, Maryland and were received officially by the Archbishop Martin John Spalding some days later at St. Francis Xavier Church which was to be their home. As the new year began, Vaughan consecrated the mission to the Sacred Heart of Jesus and named his missionaries ‘Josephites’. Father Dowling was appointed the first American provincial of the Josephite mission, and pastor of St. Francis Xavier church. The church was originally bought by Michael O'Connor (a former bishop of Pittsburgh and Erie) to serve the African-American community. The building was owned by the Jesuits, which ultimately led to a conflict. The church was heavily in debt supporting, in addition, an orphanage, school, and African-American sisterhood. The Jesuits agreed to permit the Josephites to assume management of everything including the debt. Moreover, the former would retain the right to reclaim and sell the property without conditions. This state of affairs was highly unsatisfactory to Vaughan, and, unfortunately, Bishop Spalding died in February 1872, before anything could be resolved.
A mission to Africa itself, however, was not far from Vaughan’s mind. Now he dreamt of founding in the post-Civil War United States a missionary college that would train African Americans to lead the evangelisation of the continent from which they had been exiled. In the meantime he set off on a tour of the southern states, inspecting places where his men might be called to work, appealing for funds and looking out for candidates. He was away seven months, and in that time he visited Cincinnati, Louisville, St. Louis, Charleston, Savannah, Richmond, Memphis, Vicksburg, Natchez, and New Orleans. Eventually, Josephite missions would be established in Louisville, Charleston, and upper Marlborough, Maryland. Having noted the possibilities and difficulties in the apostolate he had undertaken, he left for New York to appeal in its principal churches for the African-American mission and for students’ burses. There he met the twenty-one year old New Yorker John Slattery who would be ordained five years later at Mill Hill, and would eventually lead the independent society of American Josephites. Before returning to England, Vaughan went to sow the missionary seed in Canada.
When Vaughan set sail for England in June 1872, in Baltimore there was already a chapel, a school, a home for the aged poor, the beginnings of an industrial school and an inter-racial brotherhood. The death of the well-disposed Archbishop Spalding shortly after the missionaries’ arrival had been a setback, though less serious than the loss of the leader Cornelius Dowling from typhoid fever after seven months on the mission. Father Dowling was to die of typhoid in August 1872. Vaughan then appointed James Noonan as his successor. Never happy with this commitment, Noonan was to endure as the mission's second provincial until October 1877, when Vaughan finally granted his release.
Vaughan would make a second visit to the U.S. in January 1875, bringing with him a group of new priests, including Canon Benoit, William Hooman, Frederick Schmitz, John Greene, and Richard Gore, brother of James Gore, as well as Brother Edward Murphy. At this time, Vaughan consolidated connections between the American mission and Mill Hill by drawing up official rules for the Josephite missionaries to live and work by.