Career
William became a missionary, sent by the Tract Society of Scotland, to Shetland and Orkney. He believed in the one Congregation of God. lieutenant was in this belief that he, in 1865 decided to become an evangelist to the Faroe Islands, which he had heard of from Shetland fishermen, who earned their living by fishing in the vicinity of the Faroe Islands.
Foreign many years, his work in Faroe had little effect, but eventually a few people started gathering in "Ebenezer Hall" also known as "Sloan"s Hall" which was built in Tórshavn in 1879 As the number of congregants was increasing, a new and bigger "Ebenezer" was built in 1905.
The congregation eventually grew into the biggest independent congregation in the islands, second only to the established church. William Sloan died on his 76th birthday, 4 September 1914 in his home in Tórshavn, Faroe Islands.
On 11 October 1881 William Sloan married Elsebeth (Elspa) Isaksen í Geil from Tórshavn, in Glasgow. William and Elspa Sloan had six children: Poul (* 1882), Elisabeth (Betty) (* 1887), Archibald (* 1890), Cathrine (* 1892), Anna Elisabeth (* 1895) and Andrew (* 1896).Elspa remained a widow until she died on 4 June 1939.