In 1844 Cadman accepted the curacy offered to him by the Rev.
Henry Montagu Villiers, Rector of
St George's, Bloomsbury in London and later
Bishop of Durham from 1860 to 1861, In 1852 Cadman accepted the Rectory of
St.George the Martyr, Southwark, one of the largest parishes in London with a nominal congregation of 30,000. The church in 1852 was capable of holding 1,000 persons but on Cadman's arrival was almost empty with its days at the centre of the local community apparently past. As
Henry Mayhew had highlighted in articles for the
Morning Chronicle in the 1840s the area contained much destitution and dire poverty. Cadman was able to fulfill a spiritual void for many and within a few months church services were full to hear Rev. Cadman preach. In January 1859 Cadman reported that there was nearly 200 voluntary agents employed in schools and institutions who met for a service at New Year to celebrate the work within the parish. Cadman was not a man to often articulate his thoughts on paper but at the inaugural
Church Congress, held at
King's College, Cambridge in November 1861, he gave expression to the system that he had adopted in Southwark. He told Congress that the mother church
was the centre of operations from which a body of volunteers worked in all parts of the community. Each clergyman was to associate with him: lay volunteers, a scripture readers, deacons, Bible women. He recommended establishing either a
National or a
ragged school in each sub-district with
Scripture lessons provided by the local clergy. Schools could be licensed for worship and lectures commenced. The local congregations were to be empowered to lead on the construction of new churches and chapels. He also recommended entrusting the help of evangelical societies including the
London City Mission and the
Church of England Young Men's Society. ==Rector of Holy Trinity Church, St Marylebone==