The history of the Catholic Church in the Winneconne area dates back to the visit of the French missionary, Father Claude Allouez of the Society of Jesus, who met with Chief Poygan on lakeshore property later deeded to Neil grimes.  On the site of the Native American village on the shores of Lake Poygan, Father Allouez established the Mission of St. Mark which endured from its founding in 1670 until 1721.

    In later years of the pioneer period, Catholics in the area were served by priests from Oshkosh parishes.  Early records establish that Mass was offered in homes of Catholic families in the village as early as 1865.

    In 1868, four lots and an old school building were purchased, the beginning of parish organization; and the parish was designated a mission of St. Peter Church in Oshkosh within the Green Bay Diocese.

    About 1870, during the pastorate of Father Clark at St. Thomas Church, Poygan, the Winneconne church was annexed to that parish as a mission.

    A former Methodist Church building was purchased by Winneconne Catholics in 1883.  It stood in the vicinity of the property now owned by the parish and was used until it was demolished by a tornado in 1885.

    For a brief period (March 1884 to May, 1885) a Father Holzknecht lived near the church in a home purchased to house a resident pastor.  At this time, Omro was annexed as a mission and was transferred from the Milwaukee Diocese to the Green Bay Diocese.

    In the summer of 1885, a new church was erected and consecrated to Our Lady under the title of her Immaculate Conception.  Indebtedness on the new structure was cleared during the pastorates of Father T. Ryan, Father Walter Fitzmaurice, and Father Lawrence Spitzelberger.

    On May 1, 1888, St. Mary Church, Winneconne, again became a mission of St. Thomas Church, Poygan, along with the Omro church.  Father Charles Gallagher, Father Kelleher, Father Francis Tully, and Father Francis Linder served the three churches until 1906.

    Father William Luby was appointed pastor of St. Thomas Church, Poygan, with its two missions in 1906; and he was named resident pastor at Winneconne in 1915 when a new rectory was constructed next to the church.  When Father Luby became a chaplain in the army in April, 1918, Father John Husslein assisted in the parish until the appointment of Father Francis Kamps as pastor in 1918.

    Father Kamps endeared himself to the parish in the brief period of his pastorate before his death in November, 1918.  Father Kamps died of pneumonia after an automobile accident.  Again the Poygan pastor assisted in the parish until the appointment of Father William Grace in December, 1919.

    In May, 1927, Father Victor Kaudy was made pastor at Winneconne with a mission at Omro.  In 1929, extensive church remodeling was completed.  A basement was built under the church, a heating plant installed, and the interior completely rebuilt and refurnished with a new sanctuary added to the original building.

    Ordination to the priesthood of Father Martin Coughlin and Father Walter Williams in 1935 marked the first time sons of the parish had received the Sacrament of Holy Orders.  Father Coughlin was ordained for the Peoria Diocese and served as associate pastor in churches in Pontiac and Peoria, Illinois, and as Pastor of parishes in Rapid City and Utica, Illinois, prior to his retirement in May 1968.  Father Williams served the Green Bay Diocese in assignments to St. Joseph Orphanage, as associate pastor in churches at Manitowoc and Green Bay, and as pastor at Lannark, Cooperstown, St. John Church, Oshkosh, and St. John the Baptist Church, Green Bay.  He retired in May, 1969.

    Another building project was initiated under Father Kaudy's leadership when plans were made for a new parish hall.  The hall, which now bears his name, was erected in 1954 and named to honor him in ceremonies in May 1970.  Father Kaudy retired in October 1968 and Father Eugene Schmidt was appointed pastor.

    During the first months of his pastorate, Father Schmidt worked with parishioners to establish a lay board to work with the trustees in the administration of parish affairs.  Soon after, a building committee was named and plans were completed for a church to serve what was then a parish of 400 units.

    The contemporary structure of brick, wood and stained glass was dedicated October 18, 1970.  As the Winneconne church grew and was built to accommodate that growth, the Poygan church, St. Thomas, steadily declined and it became a Mass station.

    When Father Cyril Van Heeswyck replaced Father Schmidt in 1973, progress in lay involvement in the affairs of the parish continued.  When Father Van Heeswyck was assigned to St. Mary's Church, Algoma, in 1984, Father Paul Vanden Hogan became pastor in Winneconne.  Previously, Father Vanden Hogan had assisted the parish with a youth program when he was spiritual moderator of Lourdes High School in Oshkosh during the 1960's.  Among his very real contributions was the establishment of a Knights of Columbus council.

    Father Leroy Smet replaced Father Vanden Hogan as pastor in late September 1988 after nearly ten years as pastor of St. Joseph Church, Phlox and Holy Family Church, Mattoon.  Quietly building on foundations laid earlier according to Second Vatican Council guidelines, he has continued growth in membership which has gathered momentum.  Membership has grown to over 700 units.