The original foundation stone was put in place on 17 March 1856 by the vicar general, Father Michael Ryan, with the first part of the cathedral being dedicated on 11 July 1858. It was first extended when construction began at the southern end of the cathedral, including the sanctuary, side chapel, lady chapel and sacristy in January 1859. Construction of the first extension finished the following year in November 1860. With further growth in the population of Adelaide, another extension was required to seat more worshippers. In November 1886, Bishop Reynolds laid the foundation stone for an extension on the eastern side for a further 200 people, as well new vestries and confessionals. These were completed in August the following year. In 1904, electric lighting was introduced.