The history of Saint Dennis Church is subtly connected to the French missionaries and voyageurs who settled the North American continent. The parish origins are intimately related to the construction of the Illinois and Michigan Canal, now recognized as a national historic landmark, and to the settlement of northern Illinois. Saint Dennis Church has a hallowed place in the history of the development of the Diocese (and later Archdiocese) of Chicago and is a charter member of the Diocese of Joliet, which celebrated its fifty year anniversary in 1998. First and foremost, the history of the Saint Dennis community is the history of the people at Lockport who, having anchored their lives in their faith, continue to blaze new paths throughout their lives.

The following account reveals the story of these people through their priests who were not much different than themselves. In pioneer days all struggled with the rugged frontier terrain. As settlement occurred they attempted to refine their surroundings and develop the neighboring community. When times became complacent some followed suit. In times of tragedy all came to the forefront. With changing times so, too, did they change.

To appreciate the complete picture we must start at the beginning of European-inspired exploration in the region. Unlike the Spanish trailblazers who tended to be more martial in their manner towards the Americas, the French voyageurs approached this New World as a multifaceted venture. These pioneers branched out through New France to spread the gospel and chart the course of passageway for people reaching America. Their America was a mercantile venture, an adventure of the soul, and a chance to touch the souls of a new people. It was with this speculation in mind that the lives of Louis Jolliet and Father Jacques Marquette were brought together. Under the orders of their respective superiors Marquette and Jolliet would set forth on a journey to chart the rivers, lands and people of middle America. Particular interest was devoted to exploring the mysterious Mississippi River.

The results of the journey down the Mississippi River by Marquette and Jolliet would set policy in New France for the next one hundred years. One of the recommendations suggested by Jolliet was for the construction of a canal at the portage used by the local natives to cross the Des Plaines River to the Chicago River. This canal would essentially link together all the waterways from the Atlantic Ocean, through theGreat Lakes, to the Mississippi River and the Gulf of Mexico. Unfortunately for the citizens of New France this canal would not be realized in their time.

In late August and early September of 1673 Father Marquette logged into his diary information on the area around what is now the Diocese of Joliet, Will County, Illinois. This information, along with everything that Father Marquette wrote on the expedition would become extremely important when Louis Jolliet's records were lost in the rapids just outside Montreal. Jolliet's attempts to shoot the rapids at Lachine instead of portaging caused the biggest setback in his life.

Ironically, fame would come to Jolliet from a portage he did make, at Chicago, and the recommendation he would make about that particular portage.

Father Marquette is credited with saying the "first Mass in Chicago" on the 15th of December 1674, one of his many firsts. Missionaries would come to the area spurred on by Father Marquette's success with the Illini and other tribes in the vicinity. Father Claude Allouez, S.J., and Father Gabriel De la Ribourde, O.F.M., would follow Marquette in quest for souls - the latter being martyred near present day Morris, Illinois. In 1699 the first permanent settlement at the southern end of Illinois territory was founded at Cahokia east of the Mississippi River near present-day St. Louis. At this site the Holy Family Mission was established by Fathers Montigny and St. Cosme from the Quebec Seminary of Foreign Missions. This settlement guaranteed steady missionary traffic through the Chicago portage to the southern mission. Fours years later Father Gabriel Marest, S.J., moved the Immaculate Conception Mission to Kaskaskia from St. Louis.

The first "permanent" church in the area was founded at the southwest tip of Lake Michigan as the Guardian Angel Mission. Between 1696 and 1701, Father Francis Pinet, S.J., and his assistant Father Julien Bineteau, S.J., interacted with the people of the area introducing them to Christian tenets. The anchor of faith was dropped into the murky waters where Lake Michigan meets the Chicago River. The citizens of New France developed trade practices in the region and their presence became commonplace. Due to friction between the New France ruling party and the Jesuits around 1701 the Guardian Angel Mission was shuttered.

The Catholic population would be served by roving missionaries over the next hundred years. The Illinois frontier, now part of the colony of Louisiana, was under the ecclesiastical jurisdiction of Quebec while the French ruled but this would soon come to an end.

With the Treaty of 1763 France relinquished all their North American holdings, except Louisiana, to the British. However, by this time Illinois was no longer a part of Louisiana. The Diocese of London would now assume the task of guiding the frontier mission of America. The British rule was short-lived, as the United States was about to come into existence. In 1774 the Diocese of Baltimore was designated to takeover the direction of the missions in the West. Reverend John Carroll, Prefect Apostolic of the United States, dispatched Father Paul De St. Pierre, O.C.D., to Illinois country which was part of Virginia colony. He ministered here for the next six years.

In 1808 settler movement westward inspired the creation of the Diocese of Bardstown, Kentucky, which acquired ecclesiastical jurisdiction over what was then known as the Northwest Territory. Bishop Benedict Flaget presided over the affairs of these souls although the War of 1812 prohibited the Bishop from venturing into the area. Because of government land grants like the Illinois Military Tract, settler movement after the War of 1812 was on the rise in the Illinois Territory. It would be these settlers who would realize the importance of the area for transportation to points westward. The idea of a canal to stimulate the region sounded like a great and profitable idea to them. As an aftermath to the War of 1812 the United States government realized the strategic need for better avenues of transportation for troop movement and set into motion public works programs which would make the canal idea a reality. The United States government in 1827 to entice investors, developers and settlers into the area issued land grants made to the state of Illinois. Now the state could seriously study canal plans in detail.