As the local Catholic population exploded in growth, the Archdiocese established new parishes which reduced St. Edward's original boundaries. First, the formation of Our Lady of Victory Church in 1906 (as a mission of St. Edward) reduced the parish's western boundaries. Then, Our Lady of Mercy Parish was founded in 1911, which reduced the eastern boundaries. 

During these early years, Father Cregan saw the need for a parish school, and on July 11, 1909, Bishop Paul P. Rhode, D.D., laid the cornerstone of our original school building on the site of the present-day parking lot. The school was completed in September 1909, but the school's opening was delayed due to the lack of teachers. The 52x110-foot building had just two stories. including a main floor semibasement containing two clubrooms, a recreation room and heating plant. The second floor contained four classrooms, intended to accommodate 240 students, living quarters for the sisters, and an auditorium. The contractors were Murphy, Peter Bartzen and Son. 

The parish school finally opened in 1910, with an enrollment of 200 students under the direction of the Sisters of St. Dominic from Springfield, Illinois. Due to the rapid increase in enrollment, Father Cregan had to purchase a 50x163-foot lot on Lowell Avenue as the site for an addition to the new school. By 1915, there were 350 families in the parish (of mostly Irish, German, and Bohemian descent), and the school educated 275 children, taught by just five Dominican sisters. That is an astonishing ratio of approximately 55 students per teacher! Indicative of how the parish and school were growing, seventy-five children received their First Holy Communion in 1915.