The foundation for the church was started on September 10, 1874 and the 30' x 50' building was completed, with altar, pews and bell and dedicated on December 8, 1874 by Reverend A. M. Quatman, Reverend Anthony S. Siebenfoercher and Reverend Homan. The church, with all furnishings, property, bell, etc. cost $3,227.50. Although appointed pastor of Kenton's church on December 28, 1871 by the Bishop of Cincinnati, records indicate that Reverend Siebenfoercher did not become Ada’s active pastor until June 1874.

Dedicated on the feast of the Immaculate Conception, the church was named Our Lady of Lourdes in honor of its patron, Mary Immaculate. The parish began as a mission from Our Lady of Lourdes church in Marysville. In 1880 it was made a mission from Immaculate Conception, Kenton; changed in 1881 to St. Patrick's of Bellefontaine; 1n 1883 and 1884 changed back to Kenton and in 1886, when LaRue obtained a resident pastor, Ada became a mission to their St. Joseph's Church and it remained so until 1946 when Ada was again made a charge of Kenton. The year before, in 1945 Ada became a part of the Diocese of Columbus. On July 12, 1948 Our Lady of Lourdes became an independent parish with the formal installation of Fr. Richard Hoch as the first resident pastor.