Around 1890, a school was established and conducted by two Benedictine sisters. Due to the economic conditions, this school was closed by the spring of 1893. In 1907, a parish school was reopened and classes were held in the church basement. In 1910, the present school property was purchased, and a new building was built. When the school was ready for students, it began with eight grades and a commercial course was offered after the eighth year. This course was dropped and a regular high school was added in 1915. The first high school graduation was held in 1920, and the last graduation was held in 1932. Ninth grade was readded in 1933 to form a junior high. This system continued through 1973.

After more than a year of construction, the new Immaculate Conception School addition was dedicated on August 30, 1964. The addition included eight classrooms, a library, administrative office, a gym with locker rooms, kitchen, and enclosed the fore tower from the old and new building. In keeping with the times, innovative programs were established at the school. A dual enrollment system with the Waterown Junior High School for the seventh and eighth grades began in the fall of 1971. Kindergarten began in the fall of 1973-1974. The late 1980's started a trend of changes at the school. Due to a decrease in enrollment, seventh and eighth grade was closed in 1985.
 

During the summer of 1989, a significant building project occured. The 1939 school was demolished, and a portion of the school was remodeled. The remodeling added four classrooms, a new library, and three office spaces. This project also created a space for preschool for 4-5 years olds to begin in the fall of 1989. In 2000 preschool for 3-4 year olds was implemented.

Along with the new project, innovative fund raising happened. In the summer of 1997, the first annual Hi-Tech Golf Tournament was held to help raise money for a new updated computer lab. Spanish was added to the school curriculum in 2001. Another milestone was made in 2002 with our kindergareten becoming the only all-day, every day program in Watertown. After-school care was started, and, in the fall of 2007, before school care was an option for parents as the Kids On Target program was implemented with the assistance of grant money.

The future looks bright for Immaculate Conception School. The 2008-2009 school year enrollment for preschool-sixth grade is 200. Immaculate Conception School is growing, and we want to share our school with our alumni and community. Our school's walls and classrooms have been freshly painted with vibrant colors and quotes. We have started various clubs and school activites for students. We invite you to see the changes and refresh your memories.