Antoni Klawiter, the Roman Catholic and, afterward, independent Polish Catholic priest, was born in Chojnice, in modern Poland, on November 12, 1836. The scholarly consensus is that he was the son of Polonized Germans; by virtue of his Kashubian birthplace and his later experience pastoring Kashubians in Winona, Minnesota, he will not have been unfamiliar with the Kashubian culture. In 1859, he was ordained a Roman Catholic priest in Włocławek, and became four years afterward one of many Polish priests who were involved with the Polish Insurrection of 1863. In late 1873 or early 1874, Father Klawiter emigrated to the United States.
Upon reaching America, Klawiter served as an assistant in various Chicago and Pittsburgh parishes. In October 1873 he became the first pastor of Saint Stanislaus Kostka in Pittsburgh, which he established in a former Presbyterian church on Penn Avenue; a parish school was established in the church basement. However, inter-parish strife forced Bishop John Tuigg of Pittsburgh to remove Klawiter from his position in 1877. As Stanley L. Cuba well observes, Klawiter's problems at his first pastorate "characterize practically all of his subsequent assignments in both Polish Roman and National Catholic Churches." Such was the case at Saint Anthony's Parish, which Klawiter founded at New Poznan, (now Farwell), Nebraska in 1878. He left New Poznan in December 1878 to help found Saint Stanislaus Kostka Church in Saint Louis, Missouri, returning to New Poznan for just enough time to alienate the parishioners at Saint Anthony and to be forced to leave. Klawiter then moved to New York State, where he pastored Saint Hyacinth's Parish in Dunkirk (1881-1884) and founded Saint Adalbert's Parish in Buffalo (1886-1890). After various intrigues forced Klawiter from the Diocese of Buffalo, he pastored Saint Stanislaus Bishop and Martyr in Newark, New Jersey (1891-1892) and Saint Stanislaus Bishop and Martyr in Meriden, Connecticut (1892-1893). His final stint as a Roman Catholic pastor began in September 1893 at Saint Stanislaus Kostka in Winona, Minnesota, which was becoming known by now as the "Kashubian Capital of America." There he began the building of a huge new church but was forced, at least partially, by a feud with the Kashubian poet turned American newspaper editor, Hieronim Derdowski, to leave Winona in the Spring of 1894.