Whilst working in Edinburgh as a clerk in the civil service, Graham was influenced and encouraged by the minister of his church, John McMurtrie, to be ordained in the ministry.

In only a few years after arriving in Kalimpong, Graham had turned into a social reformer who aimed to find a solution to what contemporary observers at that time called the "poor white problem" of British India.

One solution took the form of St. Andrew's Colonial Homes in Kalimpong, where the pure air of the Himalayas would assist in schooling "poor white" children into a useful workforce.

[2] On 24 September 1900 Graham opened St. Andrew's Colonial Homes on land leased from the Government of Bengal below Deolo hill in a rented cottage with 6 children.

This was completed in 1925 and dedicated as the Katherine Graham Memorial Chapel on 24 September, the Homes Silver Jubilee birthday.