Born July 12, 1858 in Philadelphia, was the son of Richard and Mary Ann (Dinneney) McDevitt. After graduating from La Salle College High School and La Salle College, he attended Saint Charles Borromeo Seminary. He was ordained to the priesthood in Philadelphia on July 14, 1885 by Archbishop Patrick J. Ryan.

For fourteen years, Father McDevitt served as Assistant Rector of the Church of the Nativity of the Blessed Virgin Mary in North Philadelphia. It was during this time that he began to realize and take notice of the imperfections that plagued the Catholic education system, specifically in Philadelphia. As a result of his Lasallian education, Father McDevitt believed that a great amount of good could be accomplished with young people through personal contact. This philosophy was the foundation for all the educational endeavors that McDevitt pioneered, and became the standard for which the Philadelphia Catholic School System is based. Father McDevitt was appointed as Superintendent of Catholic Schools of Philadelphia in 1899. In this position, he gained a national reputation as a Catholic educator and administrator. Father McDevitt was named a Domestic Prelate (Monsignor) on July 16, 1910.

Monsignor McDevitt was appointed the fourth Bishop of Harrisburg on July 10, 1916, and was consecrated by Archbishop Edmond F. Prendergast of Philadelphia on September 21, 1916. During Bishop McDevitt’s years in Harrisburg, ten new parishes were established and twelve new schools were opened. In addition, Catholic high schools were established in eight different areas.

Bishop McDevitt served on the Committee of the National Catholic Welfare Conference and was Chairman of the Catholic Press Department. Bishop McDevitt served three terms as President of the American Catholic Historical Society. He was also a nationally-recognized historian and writer.

In 1935, the aged and ailing Bishop McDevitt welcomed Auxiliary Bishop George L. Leech. Bishop McDevitt died November 11, 1935 after suffering from pneumonia, and was buried in Holy Cross Cemetery in Harrisburg.

As a tribute to his accomplishments and in recognition of his dedicated service to youth, two Catholic high schools – one in each of the dioceses that he faithfully served - were aptly named after Bishop McDevitt - Bishop McDevitt High School in Wyncote, PA and Bishop McDevitt High School in Harrisburg, PA.