Mercy Career & Technical High School is a private, Roman Catholic high school in Philadelphia, Pennsylvania. It is located within the Roman Catholic Archdiocese of Philadelphia. It is the only four-year co-educational Catholic vocational high school in the United States.HistoryMercy was established in 1950 by the Sisters of Mercy. The school was originally known as Mercy Technical School and did not start granting high school diplomas until 1973.