1863: Yardley is a Mission of St. Mark parish in Bristol.
September, 1900: Holy Trinity is founded out of the original Catholic parish of St. Mark in Bristol. Rev. John J. McAnany establishes Holy Trinity parish at Morrisville with Yardley as a Mission.
1900: Father McAnany celebrates Mass in the Knights of the Mystic Chain hall on Bridge Street for a short time, with but twenty Catholics in attendance. He later moves to a private house on South Pennsylvania Avenue, and then to a house on Mill Street (present site of the toll bridge), where he celebrates Mass until a church is built.
July 26, 1902: Father McAnany signs a contract to erect a one-story frame church with a tin roof.
July, 1903: A mortgage to build Holy Trinity Church is taken out.
January, 1904: A mortgage to build St. Ignatius Chapel is taken out.
January, 1906: The mortgage on Holy Trinity Church is paid off.
January 21, 1907: Father Joseph Heffernan was appointed Holy Trinity's second pastor.
March, 1907: The mortgage on St. Ignatius Chapel is paid off. (St. Ignatius was a Mission of Holy Trinity until 1920.)
July, 1915: Reverend William L. Hayes was named Holy Trinity's pastor.
February 24,1926: Nineteen lots are purchased; the sites of our present school, rectory and church.
1930: Father Hayes plans the building of a school. Perhaps the Depression is responsible for these plans being put on hold for twenty-two years!
January 25, 1949: To complete the rectangle of land on which the school is situated, Father Hayes buys the small parcel of land that eventually would become the school yard.
October, 1950: By now it is evident that the church and rectory, as well as three other Washington Street houses, are in the path of the new toll bridge across the Delaware River.
November 6, 1950: The offer to purchase the church and rectory by the Joint Toll Bridge Commission is approved.
1950: Father Joseph D. Gallagher was named pastor of Holy Trinity Parish.
November 13, 1950: Holy Trinity Church celebrates the Fiftieth Anniversary of its founding.
1950: Father Gallagher requests permission to build a church and rectory at Pennsylvania and Osborne Avenues. Cardinal Dougherty writes back informing Father Gallagher that he is to start immediately to build a school!
1951: Father Gallagher receives permission to purchase several lots and a house. The house will serve as the rectory until 1954 when a new rectory is built.
November 11, 1951: Father Gallagher breaks ground for the school/church building.
May 2, 1952: A house on Pennsylvania Avenue is purchased to be used as a convent.
September 2, 1952: Holy Trinity School opens with Mother Alfreda, IHM, as principal and four sisters filling out the faculty.
July 5, 1953: The ground breaking for the new rectory was held.
March, 1954: Holy Trinity's priests move into the rectory. When the priests vacate the property, the IHM sisters move in. The building being used as the convent is then sold.
December 4, 1955: Father Gallagher breaks ground for the church.
April 14, 1957: Holy Trinity Church is dedicated on Palm Sunday.
1953: St. Frances Cabrini parish, Fairless Hills, and St. Michael parish, Levittown, are founded from our parish boundaries.
1956: St. Joseph the Worker parish, Fallsington, becomes an independent parish, no longer a Mission of Holy Trinity.
September 25, 1958: Father Gallagher purchases land which is now occupied by the New School (YMCA).
1964: St. John the Evangelist parish is founded from our parish boundaries. Between 1952 and 1964, Holy Trinity School's population had tripled.
May 6, 1964: Father Gallagher signs a contract to build the New School.
September, 1965: New School is completed and opened.