A pupil of Thomas Rogers Kimball, Nachtigall designed a number of Catholic churches and other buildings in the state, several of which are also listed in the National Register.

The first white settlers to occupy the site of Madison were a party led by Henry Mitchell Barnes, who settled near the junction of Union and Taylor Creeks in 1867.

In 1877, they wrote to Bishop James O'Connor of the Diocese of Omaha, asking that a priest be assigned to visit the church at intervals until a permanent priest could be assigned to the parish; in apparent response to this, Franciscan missionaries based in Columbus were given the responsibility of providing for Madison County.

[15] In January 1880, the church's trustees spent $100 for five acres (2.0 ha) on a hill at the southeastern edge of town.

In the spring, a party of parishioners drove their ox teams to Wisner, about 30 miles (50 km) northeast of Madison, for the first load of lumber for the new church.

The new church was dedicated to St. Leonard of Port Maurice,[15][16] an 18th-century Franciscan priest, preacher, ascetic, and writer venerated as the patron saint of parish missions.

[14][16] In 1882, a parcel of land southeast of the church was purchased for a cemetery; a one-year-old child buried in September of that year became its first occupant.

The church was moved in two parts; when it was reconstructed, another section was added between them, increasing the building's seating capacity to 180.

Brother Leonard Darscheid, a Franciscan architect, drew up plans for a church; but financial constraints precluded its construction.

Construction of the basement church began in July 1902, services were held there beginning in September 1902, and it was dedicated in February 1903.

[18][19][20] The school opened in September 1903, with two classrooms staffed by two members of the Sisters of the Presentation of Dubuque, Iowa.

[23][24] In 1911, a two-story eight-room brick rectory designed by Nachtigall was begun; it was completed and furnished in 1912, at a cost of $10,374.

The cornerstone was laid and construction begun in May; the church was completed by the end of November, and formally dedicated on December 4.

In its 110-foot (34 m) tower was a clock with four six-foot (1.8 m) dials, and a peal of three bells, contributed by the citizens of Madison; beside summoning the parishioners to Mass, these rang the quarter-hours, marking time for the residents of the city and the surrounding rural areas.

At the same time, increasing mechanization reduced the need for farm labor, pushing agricultural wages downward and rural unemployment upward.

[33] St. Leonard's paid off its remaining debt, held a mortgage-burning ceremony in 1946, and began raising funds for a new school.

[17] The new building was completed and opened for classes in August 1954; the old school, which had begun life as the first St. Leonard's Church, was demolished that fall, and its site became a parking lot.

[38] The centennial of the church building was celebrated in December 2013, at a bilingual Mass conducted by Elden Curtiss, archbishop emeritus of the Archdiocese of Omaha.

The walls are made of mosaic gray pressed brick trimmed with Bedford stone, rising from a rock-faced limestone foundation, and are about 40 feet (12 m) high.

Below the tower, a flight of seventeen steps ascends to the church's main entrance, via a set of double doors through a semicircular archway.

[14][48] On the Gospel side of the chancel is a large hand-carved wood pulpit, decorated with carved figures of the four Evangelists.

Like the communion rail, the side altars, and the pulpit, it is made of hand-carved wood decorated with small onyx columns.

In separate niches on either side of the crucifixion scene are statues of St. Boniface and St. Patrick, representing the German and Irish ethnicity of the parish in the early 20th century.

In the center, God the Father and Jesus are enthroned on a cloud; a stained-glass skylight at the top of the dome depicting the Holy Spirit completes the Trinity.

These include St. Cecilia, patron saint of the Archdiocese of Omaha, and a pair of windows depicting St. Boniface and St.

[14][47] In the 1989 form nominating it for the National Register of Historic Places, it was noted that the church had undergone only minor alterations, including an interior redecoration in 1964, the replacement of roof slates with asphalt shingles in 1977, and the addition of a concrete ramp for access by the handicapped in 1986.

[49] The rectory, located just south of the church, was designed in Neoclassical style, with Romanesque Revival elements.

[50] An open porch occupies the whole of the west frontage, facing the street, and wraps around to cover half of the south side.

[52] The front (west side) of the garage is made of the same mosaic gray brick that was used for the construction of the church and the rectory.

On the west side, north of the car entrance, is a window with beveled lead-glass panes, which appear clear from the outside but red from inside the building.