The facilities that had been the education center for the elementary and high school had been destroyed by a fire in 1938, which precipitated Delone's donation.

The cornerstone of the new school was laid in 1939, and the new building was dedicated by Archbishop Amleto Giovanni Cicognani, Apostolic Delegate to the United States, on September 2, 1940.

Delone Catholic High School serves the youth of parishes in Hanover, McSherrystown, Littlestown, Spring Grove, Abbottstown, New Oxford, Bonneauville, Gettysburg, Fairfield in Pennsylvania; and Westminster, Emmitsburg, Reisterstown, Taneytown and Glyndon in Maryland.

The girls' basketball team won the Pennsylvania Interscholastic Athletic Association State Championship in 2002-03, 2003–04 and 2004–05, all in PIAA section AA.

[6] In 2004-05, Delone won the state championship with a 47-43 win against Westmont Hilltop High School at the GIANT Center in Hershey, Pennsylvania.

[7] The boys' basketball team won the 1988-89 Class AA State Championship with a 68-61 win over Brentwood High School.

Sprinter Maggie Borden was 2001 and 2002 state champion in the 400 meters, and was named Division B Track and Field Player of the Year.

[9] James "Jimmy" Smith won the PCIAA State Wrestling Championship in the unlimited weight class in 1972, before Catholic high schools could compete in PIAA competition.