The Church of the American Ceylon Mission (CACM) has roots in the work of early missionaries in the Jaffna peninsula of Sri Lanka from 1813 onward. These were missionaries sent by the American Board of Commissioners for Foreign Missions (ABCFM), the predecessor body of UCC mission that celebrates over 200 years of global mission, and a predecessor body of today's Global Ministries.
The early congregational church of the Jaffna peninsula joined the church union movement in 1947 and became the Jaffna Diocese of the Church of South India. Since 2006 the CACM has been separate from the Jaffna Diocese of the Church of South India (JDCSI). CACM maintains its long-standing partnership with Global Ministries.