Born Ignacy Karol on January 9, 1855 in Czarnakowa, Poznan, Fudzinski was educated in the local school system of Poznan before sailing for America. Having arrived in Albany, NY, he entered the German province of the Franciscan Minor Friars and was given the name Hyacinth (Jacek). After he pronounced his first vows, Jacek was sent to study at the famous Lovanium University in Belgium and, in 1877, was ordained to the priesthood by Bishop Karol Anthonis. Upon completion of his studies in Belgium he was sent to Italy and assigned to prepare for his ministry as an apostolic confessor. In Italy, he was to work with the Poles and Germans. The next 15 years saw Fudzinski laboring at the Vatican and the Lateran Basilica as well as continuing his studies for a masters degree in theology and a doctorate in canon law.

Constantly expressing a deep concern for the needs of his fellow Poles arriving in the United States in large numbers, Fudzinski was finally allowed to transfer back to America. Shortly after his return, he was elected provincial of the German Franciscans in Syracuse, NY.

Bishop Quigley sought Ojciec Jacek's help with the problem of the increasing number of Poles coming to Buffalo and the rise of an Independent church among them. Fudzinski arrived in Buffalo early in 1898 and was commissioned to found another Polish parish on the city's East Side. The young Franciscan purchased land and buildings at the corner of Kent and Clark Streets; and by April of that year a temporary church was completed. In June, Bishop Quigley solemnly blessed the church during the celebration of Corpus Christi, in whose honor the parish was named. Since the structure was considered only temporary, Fudzinski immediately set out to collect funds for the purpose of building a church/school structure. This was completed in November 1898.

In 1905, Ojciec Jacek petitioned for an won approval to form a Polish province of Minor Conventuals – St. Anthony's. In the proclamation of the new province, any Polish member of the conventuals who decided to join the new society was authorized to do so. Fudzinski became the first provincial of the newly organized order, now head quartered in buffalo, NY. Shortly after the order's formation, requests for Polish-speaking priests to minister the new immigrant groups began to come in from several dioceses.

Being an avid patriot, Ojciec Jacek was a strong supporter of all Polish national functions. He and his friars made house collections for Polish relief services, for the Polish Army in France (Blekitna Armia Hallera) and other worthy causes. He was decorated with the Polish "Polonia Restituta" medal as well as the "Mieczy Hallerowskie" for his tireless efforts.

It was also thanks to Fudzinski's efforts that the Franciszkanki – Franciscan Sisters of St. Joseph of the German Franciscan province, he was visiting a parish in Trenton, NJ. There he met Sister Koletta Hilbert, a young nun of the St. Charles Borromeo Order. She and her three novices were ordered back to the motherhouse in Poland. The four were seeking a way to remain in the United States when they met Ojciec Jacek. He personally arranged for them to stay in America and found their own religious order, the Franciscan Sisters of St. Joseph. After having organized Corpus Christi Parish, he brought the nuns to Buffalo to staff the school. Their first motherhouse was erected on Clard Street in Buffalo in 1907.

With his parish growing so much larger, Fudzinski was now faced with the problem of overcrowding. In 1909, the third church structure of the parish – the twin-steepled red stone building was completed and solemnly consecrated by the first Polish bishop in America – Pawel Rhodes.

Ojciec Jacek's advice was frequently sought on matters regarding the Polish community, especially the organization of new parishes and combating the Independent movement. During his last tenure as provincial, a disagreement arose with the Franciscans in Syracuse where, until 1917, the your Polish novices studies. As a result, the formation department was brought to Athol Springs, NY. By this time, there were approximately 100 men in St. Anthony Province.

At the 1920 provincial chapter, Ojciec Eustachy Bartosiewicz was chosen to succeed Fudzinski as provincial. Though aging, the latter remained active in the affairs of the order as well as in the administration of his parish, Corpus Christi.

Shortly after having celebrated his 50th anniversary as a Franciscan priest, Ojciec Jacek sailed for Rome as part of a Franciscan delegation. Taking advantage of his opportunity to be in Europe, he traveled to Poland to visit and regain his strength. But he died on May 14, 1925 at the Franciscan Friary in Poznan, An elaborate funeral service was held in Poznan before the body of the former provincial was returned to Buffalo for interment in Cheektowaga's St. Stanislaus Cemetery.