In 1819, the Catholic Committee (Messrs Fitzgerald, De Ridder, Manget, Milne and Franckland) made a request for the construction of a church at Brickdam on a portion of the old parade ground.

Small and plainly designed, this church was replaced by the Lady Chapel, built on the southern side of Camp and Hadfield Streets.

The foundation stone for St. Mary's Chapel was laid in the presence of Governor Sir Francis Hincks on 21 April 1868.

On the next Sunday (9 March) Catholic Mayor of Georgetown, Francis Dias, called a meeting where it was decided to raise funds for a new cathedral.

Granite stone came from the Dalli and Wolga quarries on the Essequibo River, and the sand came from Leguan Island.