The assistance of Catholic French troops during the American Revolution helped to abate anti-Catholic sentiment in all of the 13 original colonies.

To accommodate the increasing number of worshipers, Bishop Michael Egan of Philadelphia worked with local backers to construct St. John the Evangelist in 1814, the first Catholic parish in New Jersey.

[5] However, when Pope Pius IX erected the Diocese of Newark in 1853, he reunited the state of New Jersey as its initial territory.

[3] The pope designated the Church of St. Mary of the Assumption as its cathedral and appointed Michael J. O'Farrell of New York as the first bishop of Trenton.

[3] According to historian John Shea, O'Farrell's efforts to establish Catholic institutions in South Jersey "...did not fail to excite hostility".

During his tenure, O'Farrell erected several new parishes and missions, and established an orphanage in New Brunswick and a home for the elderly in Beverly.

During his tenure, McFaul erected an orphanage at Hopewell,[9] a home for senior citizens at Lawrenceville,[10] and Mount St. Mary's College at Plainfield, along with many parishes and schools[11] In 1909, McFaul created a controversy when he accused the professors at American colleges and universities of an "upbuilding of a cynicism and intimacy with immoral ideas.

[13] After McFaul died in 1917, Pope Benedict XV appointed Thomas Walsh from the Diocese of Buffalo as the third bishop of Trenton.

[14] In 1910, Walsh introduced the Religious Teachers Filippini into the diocese to work among the Italian immigrants in St. Joachim's Parish in South Trenton He built a motherhouse for them in Ewing Township.

[17] In 1933, the Religious Teachers Filippini established Villa Victoria Academy, an all-girls middle and high school.

[15] To replace McMahon, Pius XI appointed Moses E. Kiley of the Archdiocese of Chicago as bishop of Trenton.

[21] The Diocese of Trenton now had a Catholic population of 210,114 in eight counties with 212 diocesan priests, 121 parishes and 70 parochial schools.

Much of the growth of the Catholic population in the Diocese of Trenton took place during the episcopacy of Bishop George W. Ahr, from his appointment in 1952 by Pope Pius XII to his retirement in 1979.

He also championed the diocese's teen talk show, Realfaith TV, which was televised and webcast throughout North America.

In 2009, Bishop inaugurated the "Led By the Spirit," plan, restructuring of the diocesan administrative structure that better supports the priorities.

[27] In 2010, Pope Benedict XVI named David M. O'Connell, president of Catholic University of America in Washington, D.C. as coadjutor bishop of Trenton.

Becker pleaded guilty to one count of second-degree sexual assault in June 2007, but died before sentencing.

along with the Archdiocese of Newark and Diocese of Metuchen, reached a settlement with sexual abuse victims of former cardinal Theodore McCarrick.

[34] In August 2012, Timothy Schmalz, a Catholic University graduate, concocted a plan to expose Matthew Riedlinger, who had sexually harassed him and several over a period of several years.

Apura pleaded guilty in August 2015 to aggravated criminal sexual contact and was sentenced to three years in prison.