Our parish history begins in 1836 when Father Samuel Mazzuchelli, O.P. came to Potosi and united area Catholics to form St. Thomas Parish. He built a log cabin church where the St. Thomas parking lot now lies.

Our first pastor was appointed by Bishop Matthias Loras of Dubuque, Iowa. Father James Causse became the first pastor in 1840. Father Causse built the first school building in 1843. Our tradition of Catholic education has continued in our community ever since.

Tragedy struck in 1849 when cholera wiped out a quarter of the population of Potosi. Most of the remaining miners left to seek their fortunes in gold in California. St. Thomas soon became a small mission parish of Dutch Hollow (now Tennyson).

German speaking immigrants established their parish in the mid-1840's, in what is now known as Tennyson. Father Andrew Tusch was the founding pastor of St. Andrew in 1846. In 1847, the first St. Andrew School was built.

Father Nicholas Thill was pastor during the construction of the present St. Andrew Church during the years of 1874 - 1877. In 1921, Father Joseph Scheffer founded St. Andrew High School, an institution which lasted 40 years.

St. Thomas and St. Andrew continued as separate and distinct parishes into the middle of the 20th century. In 1946, the parishes became part of the newly created Diocese of Madison.

In 1964, the parishes jointly built the new Ss. Andrew-Thomas School on Highway 61.

In 1971, the two parishes were combined into Ss. Andrew-Thomas Parish with a single pastor and a single system of parish administration and accounting.

Father Stephen Brunner is the current pastor of Ss. Andrew-Thomas Parish.

During the summer and fall of 1999, a handicap accessible bathroom was installed, as well as, new playground equipment.

Our physical facility has received several necessary repairs due to a leaking roof.

During the summer of 2003, a pitched, metal roof was constructed. A rainstorm in August left us with a great deal of water damage. As a result, all ceiling tiles, floor tiles, and bulletin boards needed to be replaced. The roof project was completed in October of 2003. The repairs from the water damage were completed in the summer of 2004.

February 15-17, 2012 , SS. Andrew-Thomas School had their site visit from WRISA. As a result of their visit they recommended to WRISA that our school receive re-accreditation . The WRISA Board of Directors is the sole authority in determining the accreditation status of a school.

Quote from the chairperson of the visiting team.
" The dedication of the principal and staff make it easy to understand why generations of the community have attended SS. Andrew-Thomas School. The Visiting Team found the parents supportive and complimentary of the school. We found that the parish members are committed to the school and willing to help in any way they can.
This is evident in the stewardship given to the school by so many parents and non-parents alike, and the energy put into fundraising efforts. Every stakeholder we interviewed, without exception, expressed his or her desire to see SS. Andrew-Thomas grow and continue to provide Christian based, quality education for generations to come."

In June, 2013 an automatic handicapped front door was installed at the school. We received a grant from the Apostolate to the Handicapped, Diocese of Madison for this purpose. We also insured the safety of all by installing a security system that was completed in July, 2013.

November, 2013 saw the completion of providing every classroom including the science lab with Smartboards and LCD projectors. We are grateful to the Dubuque Racing Assn and Staples for grants received in helping us complete this project.

In December, 2013 the school received a grant from the Ann and Leo Stoll Jr. Charitable Trust Foundation that provided the school monies for the purchase of mini-ipads for teachers and for instruction with ipads for one classroom of students at a time.

In April, 2014, 21 classroom pictures that hung in the front hallway were refurbished. Many thanks to SS. Andrew-Thomas parishioners for their generosity and to Wendy and Roger Scholbrock for their hard work in restoring the frames and pictures.

In June, 2014, all classrooms received new blinds. Thanks to the generosity of the SS. Andrew-Thomas parishioners.

In June, 2014,  our gym ventilation was improved with the addition of 4 new industrial fans with safety cages. Thanks to a  Dubuque Racing Association grant.

Sunday, May 3, 2015 marked an important celebration for SS. Andrew-Thomas School. The school celebrated 50 years of being in the present school. The celebration began with a 10:00A.M. mass at Saint Andrew Church followed by the planting of an anniversary tree in front of the school. One of the alumni who was a member of the first class 50 years ago, spoke to over 300 attendees about the significance of his education at SS. Andrew-Thomas School and the remarkable loyalty and generosity of the parishioners of SS. Andrew-Thomas School. Their continuous,  unwavering support of Catholic  education celebrates 175 years in 2017.  The 50th anniversary event also hosted a school student performance, time capsule presentation and a video presentation of students over the years. A lovely luncheon and  reception ended a glorious day. Truly , it was a day the Lord had made and all went home renewed by the love of friends.

In November, 2017, SS Andrew-Thomas School received a grant from the Ann & Leo Stoll Jr. Charitable Trust to purchase Chrome books which allows for the 1st-8th grade to be 1:1, plus a charging cabinet.

In October 2018, our school received a $20,000 grant from the Dept. of Justice for new classroom doors, cameras throughout the school and entrances, a new key fob system, and laminate for all entrance doors.

Our faith community is committed to continuing our long tradition of Catholic education.