Immaculate Conception, Waukegan, is one of the oldest parishes in northern Illinois. It was founded in 1841 by Irish settlers in Lake County. In 1843 Michael Dulanty (1799-1886), originally from Tipperary, Ireland, purchased two lots in Little Fort (now Waukegan) for the church on water-street.

“Architect, Joseph W. McCarthy (1884-1965), designed a Georgian Colonial structure, closely resembling the style of the first church. The design was significant as it was considered very American and not typical for a Roman Catholic Church. The church's spire stands 158 feet, and at the time, was the tallest structure in Waukegan. The bell from the first church was placed in the new church's spire”. The church has 16 Corinthian columns of marble in various hues, wrought bronze fixtures, and crystal chandeliers. A hand carved American walnut reredos framing the altar and icons.

The first mass held in the current church was celebrated by Reverend Francis Shea, December 8, 1929, on the Feast of the Immaculate Conception, and was dedicated on May 11, 1930 by George Cardinal Mundelein, Archbishop of Chicago. Cardinal Mundelein had taken a personal interest in Waukegan having one of the finest churches in the diocese.