The building was designed by the architect Robert Cary Long Jr. in 1844 and the cornerstone was laid on Tuesday September 10 of that year, at which time Bishop William Rollinson Whittingham wrote: "I cannot doubt that its beautiful edifice, when finished in the autumn, will be fully occupied by as regular and devout worshipers as now fill the little upper room, where prayer is wont to be daily made through so large a portion of the year.

[4] The altar area is set out with encaustic tile from Mintons, and the glass in the Gothic windows contains a depiction of the Good Shepherd produced by Tiffany & Co.

[10] Bishop Whittingham wrote that “there are larger, more costly, and more splendid churches in Baltimore, but there is none in my judgement so well adapted to make the worshipper feel he must ‘keep his foot’ for he is in the house of God.”[11] Mount Calvary was founded shortly after the publication in England of the Tracts for the Times, when the Oxford Movement neared its height.

"[15] In 1879, eleven local Episcopalian ministers published a pamphlet[16] objecting to a mission held at Mount Calvary, led by Basil W. Maturin,[17] that had advocated confession, the Real Presence of Christ in the Eucharist, and the Mass as a sacrifice.

Calbraith Perry and the Mount Calvary vestry nominated two candidates, one for holy orders and the other a deacon to receive priesthood, but both were objected to by the Standing Committee of the Diocese, who stated that the testimonials from the Rev.

[19] The New York Times reported, “The advanced ritualism practiced in the services has on various occasions led to spicy discussions between the Standing Committee and the Rectors of Mount Calvary."

The same article reported that one of the parish clergymen, Father Calbraith Perry, was admonished and instructed “to cease using incense and not to wear a cope.”[20] In 1894, Mount Calvary was "practically excommunicated" when Bishop William Paret – whose "stinging philippic fell from the lips" – refused to visit the church to administer the sacraments, for the church – over the bishop's objections – had installed confessionals and continued to use incense.

The cross was a gift to Mount Calvary from Mary Coale Redwood, whose son George was the first Baltimore officer to be killed in the First World War.

One of the early parishioners was Robert E. Lee, who “attended Mount Calvary Episcopal Church regularly”[25] when working on Fort Carroll in 1849 and living at 908 Madison Avenue.

In 2009, Pope Benedict XVI promulgated the apostolic constitution Anglicanorum Coetibus[45] which enabled Anglican and Episcopal parishes and individuals to enter full communion with the Roman Catholic church.

[46] Mount Calvary was elevated to the status of a parish by Steven J. Lopes on November 6, 2016, on which date he also consecrated the altar, placing within it some relics of John of the Cross.