As Catholics from European countries came to the Midwest, a number came to the Burlington area and sought to continue growing in their faith.  Before a parish was established, traveling missionary priests offered Mass in homes of Catholics as they passed through the area.  The earliest known Mass was celebrated in 1838 in the house of Mr. Nimms by Fr. Thomas Morrissey, a missionary who served in this area for twenty-three years.  In 1850, upon his death, he was buried in our Parish cemetery.

In 1842, the people of this area donated $60 to buy a horse for another missionary, Father Martin Kundig, to make sure his journeying would allow Mass to be offered in the Burlington area.

By the year 1844, the parish under the name of St. Sebastian's was formed and plans for the first church building took place.  It was built on the site, which is now the State Street parking lot.  This was the first in a long series of building projects for the parish.

Father Michael Wisbauer became the first resident pastor in 1847.  Today, Father Jeff Thielen is the ninth Pastor.  The stay of most of the eight pastors serving the parish has been long and revered. 

Land for the parish cemetery was purchased in 1846, and it became known as God's Acre.

The parish soon outgrew the first church.  In 1854, the cornerstone was laid in the "new stone church", which took five years to build.  On December 8, 1959, Bishop Henni consecrated the stone church under the title of the Immaculate Conception (St. Mary's), which was the choice of the United States Bishops as the Patroness of the country. 

The grade school begain 1860 and was served by the School Sisters of Notre Dame.  The parish and schools have been faithfully served by Notre Dame and Franciscan (OSF) Sisters.   

In 1890, work began on the current church building and it was dedicated on December 10, 1891.  On July 24, 1977, a fire destroyed most of the church.  Through the dedicated effort of many parishioners serving on a variety of committees, the church was rebuilt.  It was rededicated on the Feast of the Immaculate Conception in 1979.  Many current members of the parish will remember the centennial celebration, with Mass being offered by Archbishop Rermbert Weakland, on December 8, 1991. 

Father Van Treeck was instrumental in beginning the high school in 1920.  Marked with a colorful history of its own, it is now known as Catholic Central High School, with seventeen parishes in the area serving as sponsoring parishes. 

St. Mary's most important asset throughout its history has been the parishioners.  At present, there are 1,608 households that make up the parish family.  This represents membership of 4,576 baptized members.